Clinical practice. The incidentally discovered adrenal mass

[18F]FDG PET/CT and PET/MR in Patients with Adrenal Lymphoma: A Systematic Review of Literature and a Collection of Cases

AIM

The present study aimed to assess the existing data about Primary Adrenal Lymphoma (PAL) evaluated with FDG PET and to describe a small monocentric series of cases. A systematic analysis (from 2010 to 2022) was made by using PubMed and Web of Science databases reporting data about the role of FDG PET/CT in patients with suspicious or known adrenal lymphoma. The quality of the papers was assessed by using QUADAS-2 criteria. Moreover, from a single institutional collection between 2010 and 2021, data from patients affected by adrenal lymphoma and undergoing contrast-enhanced compute tomography (ceCT)/magnetic resonance (MR) and FDG PET/CT or PET/MR were retrieved and singularly described. Seventy-eight papers were available from PubMed and 25 from Web of Science. Forty-seven (Nr. 47) Patients were studied, most of them in the initial staging of disease (n = 42; 90%). Only in one paper, the scan was made before and after therapy. The selected clinical cases were relative to the initial staging of disease, the restaging, and the evaluation of response to therapy. PET/CT and PET/MR always showed a high FDG uptake in the primary adrenal lesions and in metastatic sites. Moreover, PET metrics, such as maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV), were elevated in all primary adrenal lesions. In conclusions, FDG PET either coupled with CT or MRI can be useful in staging, restaging, and for the evaluation of treatment response in patients affected by PAL.

[Hyperandrogenism after menopause: Ovarian or adrenal origin?]

Postmenopausal hyperandrogenism is an androgen excess originating from either the adrenals and/or the ovaries. Clinically, symptoms can be moderate (increase in terminal hair growth, acnea) or severe with signs of virilization (alopecia, clitoridomegaly). In either setting, physicians need to exclude relatively rare but potentially life-threatening underlying tumorous causes, such as adrenal androgen-secreting tumors. The objectives of this review are to evaluate which hormonal measurements (T, delta 4 androstenedione, 17 OH progesterone, SDHEA, FSH, LH) and/or imaging (pelvic ultrasound, MRI or adrenal CT-scan) could be useful identifying the origin of the androgen excess. Our review illustrates that the rate of progression of hirsutism and/or alopecia, and serum testosterone levels are in favor of tumors. Pelvic MRI and adrenal CT-scan are useful tools for identifying the different causes of androgen excess.

Management of concurrent aortic stenosis and pheochromocytoma

A man in his mid 60s with known aortic stenosis developed progressive symptoms. Echocardiography confirmed severe calcific aortic stenosis. Further evaluation revealed an elevated white blood cell count leading to a diagnosis of chronic lymphocytic leukaemia. CT of the abdomen revealed a left adrenal mass, confirmed by MRI. 24-hour urine catecholamines were elevated, confirming the diagnosis of a pheochromocytoma.This case was complicated by the concurrent aortic stenosis and pheochromocytoma, requiring considerable multidisciplinary teamwork to develop a safe management strategy. A decision to perform a transcatheter aortic valve replacement (TAVR) with alpha and beta blockade with monitored anaesthesia care followed by laparoscopic adrenalectomy and postoperative haemodynamic control was made. A successful TAVR procedure was performed, complicated only by postoperative transient atrial tachycardia followed 6 weeks later by a laparoscopic robotic-assisted left adrenalectomy. The patient recovered fully and was discharged 2 days later.

Mutational landscape of non-functional adrenocortical adenomas

Adrenal incidentalomas are the most frequent human neoplasms. Recent genomic investigations on functional adrenocortical tumors have demonstrated that somatic mutations in PRKACA and KCNJ5 responsible for the development of adrenocortical adenomas (ACAs) are associated with hypercortisolism and aldosteronism, respectively. Several studies have identified CTNNB1 mutations in ACAs and have been mostly involved in the tumorigenesis of non-functional ACA (NFACA). However, integrated genomic characterization of NFACAs is lacking. In the current study, we utilized pan-genomic methods to comprehensively analyze 60 NFACA samples. A total of 1264 somatic mutations in coding regions among the 60 samples were identified, with a median of 15 non-silent mutations per tumor. Twenty-two NFACAs (36.67%) had genetic alterations in CTNNB1. We also identified several somatic mutations in genes of the cAMP/PKA pathway and KCNJ5. Histone modification genes (KMT2A, KMT2C, and KMT2D) were altered in 10% of cases. Germline mutations of MEN1 and RET were also found. Finally, by comparison of our transcriptome data with those available in the TCGA, we illustrated the molecular characterization of NFACA. We revealed the genetic profiling and molecular landscape of NFACA. Wnt/β-catenin pathway activation as shown ssby nuclear and/or cytoplasmic β-catenin accumulation is frequent, occurring in about one-third of ACA cases. cytochrome P450 enzymes could be markers to reveal the functional status of adrenocortical tumors. These observations strongly suggest the involvement of the Wnt/β-catenin pathway in benign adrenal tumorigenesis and possibly in the regulation of steroid secretion.

Cardiovascular risk factors in mild adrenal autonomous cortisol secretion in a Caucasian population

Cardiovascular risk factors could be present in mild adrenal autonomous cortisol secretion (MACS). However, the most frequent cardiovascular risk factors in MACS have not been established. The aim of the presseent study was to analyse the difference in cardiovascular risk factors in patients with MACS in comparison to those with non-functioning adrenal tumour (NFAT). A total of 295 patients with adrenal incidentaloma were included in this retrospective study. We divided our group into those who showed suppression in 1 mg overnight dexamethasone suppression test (DST) (NFAT) (serum cortisol level ≤1.8 μg/dL) and those who did not show suppression in the DST (MACS) (serum concentration of cortisol > 1.8 μg/dL and ≤5 μg/dL). In the studied groups, we analysed the presence of cardiovascular risk factors, such as obesity, prediabetes, type 2 diabetes mellitus (T2DM), hypertension, hyperlipidaemia, chronic kidney disease and cardiovascular events. In our study, 18.9% of patients were defined as MACS. Importantly, T2DM was diagnosed in 41% of MACS vs 23% of NFAT (P < 0.01) and higher frequency of occurrence of hyperlipidaemia in NFAT (72.4%) vs MACS (53.6%) (P = 0.01) was observed. We did not observed differences in the frequency of obesity, hypertension, chronic kidney disease, prediabetes, atrial fibrillation, stroke, ST and non-ST elevation myocardial infarction and coronary angioplasty between patients with MACS and NFAT (all P > 0.05; respectively). In MACS, T2DM is more prevalent than in NFAT; hyperlipidaemia is more prevalent in NFAT. Accordingly, no differences were found in the incidence of obesity, hypertension, prediabetes, chronic kidney disease between studied groups as well as cardiovascular events.

Development and validation of model for sparing adrenal venous sampling in diagnosing unilateral primary aldosteronism

CONTEXT

Current guidelines recommend adrenal venous sampling (AVS) to identify unilateral primary aldosteronism (UPA) before offering adrenalectomy. However, AVS is costly and technically challenging, limiting its use to expert centres.

OBJECTIVE

To establish a model to predict UPA, and therefore, bypass the need for AVS prior to surgery.

DESIGN AND SETTING

The model was developed in a Chinese cohort and validated in an Australian cohort. Previously published prediction models of UPA were also tested.

PARTICIPANTS

primary aldosteronism patients with a definite subtyping diagnosis based on AVS and/or surgery.

MAIN OUTCOME MEASURE

Diagnostic value of the model.

RESULTS

In the development cohort (268 UPA and 88 bilateral primary aldosteronism), combinations of different levels of low serum potassium (≤3.0 or 3.5 mmol/l), high PAC (≥15-30 ng/dl), low PRC (≤2.5-10 μIU/ml) and presence of unilateral nodule on adrenal CT (>8-15 mm in diameter) showed specificity of 1.00 and sensitivity of 0.16-0.52. The model of serum potassium 3.5 mmol/l or less, PAC at least 20 ng/dl, PRC 5 μIU/ml or less plus a unilateral nodule at least 10 mm had the highest sensitivity of 0.52 (0.45-0.58) and specificity of 1.00 (0.96-1.00). In the validation cohort (84 UPA and 117 bilateral primary aldosteronism), the sensitivity and specificity of the model were 0.13 (0.07-0.22) and 1.00 (0.97-1.00), respectively. Ten previous models were tested, and only one had a specificity of 1.00 in our cohorts but with a very low sensitivity [0.07 (0.04-0.10) and 0.01 (0.00-0.06) in our development and validation cohorts, respectively].

CONCLUSION

A combination of high PAC, low PRC, low serum potassium and unilateral adrenal nodule could accurately determine primary aldosteronism subtype in 13-52% of patients with UPA and obviate the need for AVS before surgery.

Detection of incidental adrenal nodules on computed tomography by radiographers

INTRODUCTION

This research investigated whether radiographers' age, qualifications, shift rotations and years of post-qualification experience as a radiographer affect the detection rate of incidental adrenal nodules, also known as adrenal incidentalomas in Malta. Additionally, local statistics of adrenal incidentaloma findings were evaluated.

METHODS

This research consisted of two phases and employed a non-experimental, cross-sectional quantitative approach. Phase 1 comprised of a self-designed data collection sheet to retrospectively determine the occurrence of recalled computed tomography (CT) examinations resulting from an adrenal incidentaloma finding during a six-month period between July 2020 and December 2020. In phase 2, a self-designed questionnaire with anonymised CT scan images (n = 30) displayed on ViewDex (Viewer for Digital Evaluation of X-ray images) was prospectively completed by CT radiographers (n = 23) to identify adrenal incidentalomas on the images.

RESULTS

In phase 1, adrenal incidentalomas were present in 1.4% of contrast-enhanced CT (CECT) examinations (n = 12139), out of which, 79.8% were not acknowledged by the radiographers on the initial scans and patients had to be recalled for a dedicated adrenal CT scan. In phase 2, a statistically significant (p < 0.05) relationship was determined between the radiographers' qualifications, shift rotations and years of post-qualification experience as a radiographer, with their detection rate of adrenal incidentalomas.

CONCLUSION

Findings suggest that radiographers' qualifications, shift rotations and years of post-qualification experience were found to be statistically significant factors affecting their detection rate of adrenal incidentalomas. These could have contributed to one of the reasons for recalling patients, which in turn results in an added burden to both the patient and the Radiology Department.

IMPLICATIONS FOR PRACTICE

Detection of adrenal incidentalomas by radiographers has a direct impact on clinical practice. If identified during the initial CT examination and a further delay scan is performed, this will benefit patients by reducing the risks of additional radiation and potential risks from contrast media administration; prompt diagnosis and treatment. While the Radiology Department benefits in terms of cost effectiveness, work load and appointment scheduling.

The 1 mg overnight dexamethasone suppression test: a danger to the adrenal gland?

PURPOSE OF REVIEW

The 1 mg overnight dexamethasone suppression test (ONDST) with a cutoff cortisol value of 1.8 mcg/dl (50 nmol/l) is routinely used for the assessment of incidental, benign adrenal nodules. Patients with an abnormal test are diagnosed with mild autonomous cortisol secretion (MACS). This timely commentary reviews the origins of the ONDST, its relationship to the diagnoses of MACS, and whether this is clinically relevant for clinical care.

RECENT FINDINGS

Millions of incidental adrenal nodules are found on CT scans annually. Several papers in the last three years discuss and advocate for the diagnose of MACS via the ONDST.

SUMMARY

An ONDST cutoff of 1.8 mcg/dl (50 nmol/l) in patients with no clinical features of Cushing's syndrome will produce false positive results and a diagnosis of MACS that could result in unnecessary adrenalectomy.

Targeted metabolic profiling of urinary steroids with a focus on analytical accuracy and sample stability

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A robust and selective LC-MS/MS method for quantification of 11 urinary steroids was developed and validated.

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Optimized preparation of calibration standards improves method linearity and accuracy.

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Pre-analytical sample stability was extensively validated.

Introduction

Methods

Results

Conclusions

Is the Adrenal Incidentaloma Functionally Active? An Approach-To-The-Patient-Based Review

Adrenal incidentalomas are a common occurrence. Most of them are adrenocortical adenomas that do not cause harm and do not require surgery, but a non-negligible proportion of incidentalomas is represented by functionally active masses, including cortisol-secreting adenomas (12%), pheochromocytomas (3–6%), aldosterone-secreting adenomas (2–3%), as well as malignant nodules, such as adrenocortical carcinomas (2–5%), which can be either functioning or non-functioning. All patients with an adrenal incidentaloma should undergo a few biochemical screening and confirmatory tests to exclude the presence of a functionally active mass. In this approach-to-the-patient-based review, we will summarize current recommendations on biochemical evaluation and management of functionally active adrenal incidentalomas. For this purpose, we will present four case vignettes, whereby we will describe how patients were managed, then we will review and discuss additional considerations tied to the diagnostic approach, and conclude with practical aspects of patient perioperative management. To improve the perioperative management of patients with functional adrenal incidentalomas, multidisciplinary meetings are advocated.

Evaluation of the T2-weighted (T2W) adrenal MRI calculator to differentiate adrenal pheochromocytoma from lipid-poor adrenal adenoma

OBJECTIVES

To evaluate the T2-weighted (T2W) MRI calculator to differentiate adrenal pheochromocytoma from lipid-poor adrenal adenoma.

METHODS

Twenty-nine consecutive pheochromocytomas resected between 2010 and 2019 were compared to 23 consecutive lipid-poor adrenal adenomas. Three blinded radiologists (R1, R2, R3) subjectively evaluated T2W signal intensity and heterogeneity and extracted T2W signal intensity ratio (SIR) and entropy. These values were imputed into a quantitative and qualitative T2W adrenal MRI calculator (logistic regression model encompassing T2W SIR + entropy and subjective SI [relative to renal cortex] and heterogeneity) using a predefined threshold to differentiate metastases from adenoma and accuracy derived by a 2 × 2 table analysis.

RESULTS

Subjectively, pheochromocytomas were brighter (p < 0.001) and more heterogeneous (p < 0.001) for all three radiologists. Inter-observer agreement was fair-to-moderate for T2W signal intensity (K = 0.37-0.46) and fair for heterogeneity (K = 0.24-0.32). Pheochromocytoma had higher T2W-SI-ratio (p < 0.001) and entropy (p < 0.001) for all three readers. The quantitative calculator differentiated pheochromocytoma from adenoma with high sensitivity, specificity, and accuracy (100% [95% confidence intervals 88-100%], 87% [66-97%], and 94% [86-100%] R1; 93% [77-99%], 96% [78-100%], and 94% [88-100%] R2; 97% [82-100%], 96% [78-100%], and 96% [91-100% R3]). The qualitative calculator was specific with lower sensitivity and overall accuracy (48% [29-68%], 100% [85-100%], and 74% [65-83%] R1; 45% [26-64%], 100% [85-100%], and 72% [63-82%] R2; 59% [39-77%], 100% [85-100%], and 79% [70-88% R3]).

CONCLUSIONS

T2W signal intensity and heterogeneity differ, subjectively and quantitatively, in pheochromocytoma compared to adenoma. Use of a quantitative T2W adrenal calculator which combines T2W signal intensity ratio and entropy was highly accurate to diagnose pheochromocytoma outperforming subjective analysis.

KEY POINTS

• Pheochromocytomas have higher T2-weighted signal intensity and are more heterogeneous compared to lipid-poor adrenal adenomas evaluated subjectively and quantitatively. • The quantitative T2-weighted adrenal MRI calculator, a logistic regression model combining T2-weighted signal intensity ratio and entropy, is highly accurate for diagnosis of pheochromocytoma. • The qualitative T2-weighed adrenal MRI calculator had high specificity but lower sensitivity and overall accuracy compared to quantitative assessment and agreement was only fair-to-moderate.

Incidence of malignancy in adrenal nodules detected on staging CTs of patients with potentially resectable colorectal cancer

OBJECTIVE

To measure the prevalence of adrenal nodules detected on staging CT in patients with resectable colorectal cancer, and the proportion of patients with malignant nodules among them.

METHODS

This retrospective study included 6474 patients (median age, 65; interquartile range, 56-73; 3902 men) who underwent staging CT for colorectal cancer between May 2003 and December 2018. The patients had potentially resectable colorectal cancer, including resectable hepatic or pulmonary metastases. Through retrospective CT image review, patients with adrenal nodules were identified for the prevalence of adrenal nodule. Among patients with adrenal nodules, per-patient proportions of malignant nodules, adrenal metastasis from colorectal cancer, and additional adrenal examinations (biopsy or imaging tests) were measured. A secondary analysis was performed using data from the official CT reports.

RESULTS

The prevalence of adrenal nodules was 5.6% (363 of 6474; 95% CI: 5.1, 6.2). The proportions of malignant nodules and adrenal metastasis from colorectal cancer were 0.8% (3 of 363; 0.2, 2.4) and 0.3% (1 of 363; 0.0, 1.5), respectively. 6.1% (22 of 363; 3.8, 9.0) of the patients underwent additional adrenal examination. According to official CT reports, the prevalence of adrenal nodules and proportions of malignant nodules, adrenal metastasis from colorectal cancer, and additional adrenal examination were 1.9% (125 of 6474; 1.6, 2.3), 1.6% (2 of 125; 0.2, 5.7), 0% (0 of 125; 0.0, 2.9), and 10.4% (1 of 125; 5.7, 17.1), respectively.

CONCLUSION

Adrenal nodules detected in staging CTs in patients with otherwise resectable colorectal cancers are rarely malignant.

KEY POINTS

• Among 6474 patients who underwent staging CT and had potentially resectable colorectal cancer, 363 had adrenal nodules (≥ 10 mm) detected in retrospective CT image review. • Three out of the 363 patients with adrenal nodules detected on staging CT had malignant adrenal nodules, one of whom had metastasis from colorectal cancer.

Integration of molecular imaging in the personalized approach of patients with adrenal masses

Adrenal masses are a frequent finding in clinical practice. Many of them are incidentally discovered with a prevalence of 4% in patients undergoing abdominal anatomic imaging and require a differential diagnosis. Biochemical tests, evaluating hormonal production of both adrenal cortex and medulla (in particular, mineralocorticoids, glucocorticoids and catecholamines), have a primary importance in distinguishing functional or non-functional lesions. Conventional imaging techniques, in particular computerized tomography (CT) and magnetic resonance imaging (MRI), are required to differentiate between benign and malignant lesions according to their appearance (size stability, contrast enhanced CT and/or chemical shift on MRI). In selected patients, functional imaging is a non-invasive tool able to explore the metabolic pathways involved thus providing additional diagnostic information. Several single photon emission tomography (SPET) and positron emission tomography (PET) radiopharmaceuticals have been developed and are available, each of them suitable for studying specific pathological conditions. In functional masses causing hypersecreting diseases (mainly adrenal hypercortisolism, primary hyperaldosteronism and pheochromocytoma), functional imaging can lateralize the involvement and guide the therapeutic strategy in both unilateral and bilateral lesions. In non-functioning adrenal masses with inconclusive imaging findings at CT/MR, [¹⁸F]-FDG evaluation of tumor metabolism can be helpful to characterize them by distinguishing between benign nodules and primary malignant adrenal disease (mainly adrenocortical carcinoma), thus modulating the surgical approach. In oncologic patients, [¹⁸F]-FDG uptake can differentiate between benign nodule and adrenal metastasis from extra-adrenal primary malignancies.

Optimal and novel imaging of the adrenal glands

PURPOSE OF REVIEW

Adrenal imaging forms an important role in the workup of adrenal masses. The purpose of this review is to briefly review the traditional role of imaging in adrenal diseases and highlight the most recent research and new applications aimed to improve diagnostic accuracy.

RECENT FINDINGS

The current review will focus on new applications of computed tomography (CT), MRI and PET/CT imaging, addressing the implications of artificial intelligence and radiomics in progressing diagnostic accuracy.

SUMMARY

The new applications of adrenal imaging are improving diagnostic accuracy and expanding the role of imaging, particularly with novel PET radiotracers and the use of artificial intelligence.

Radiomics utilization to differentiate nonfunctional adenoma in essential hypertension and functional adenoma in primary aldosteronism

We performed the present study to investigate the role of computed tomography (CT) radiomics in differentiating nonfunctional adenoma and aldosterone-producing adenoma (APA) and outcome prediction in patients with clinically suspected primary aldosteronism (PA). This study included 60 patients diagnosed with essential hypertension (EH) with nonfunctional adenoma on CT and 91 patients with unilateral surgically proven APA. Each whole nodule on unenhanced and venous phase CT images was segmented manually and randomly split into training and test sets at a ratio of 8:2. Radiomic models for nodule discrimination and outcome prediction of APA after adrenalectomy were established separately using the training set by least absolute shrinkage and selection operator (LASSO) logistic regression, and the performance was evaluated on test sets. The model can differentiate adrenal nodules in EH and PA with a sensitivity, specificity, and accuracy of 83.3%, 78.9% and 80.6% (AUC = 0.91 [0.72, 0.97]) in unenhanced CT and 81.2%, 100% and 87.5% (AUC = 0.98 [0.77, 1.00]) in venous phase CT, respectively. In the outcome after adrenalectomy, the models showed a favorable ability to predict biochemical success (Unenhanced/venous CT: AUC = 0.67 [0.52, 0.79]/0.62 [0.46, 0.76]) and clinical success (Unenhanced/venous CT: AUC = 0.59 [0.47, 0.70]/0.64 [0.51, 0.74]). The results showed that CT-based radiomic models hold promise to discriminate APA and nonfunctional adenoma when an adrenal incidentaloma was detected on CT images of hypertensive patients in clinical practice, while the role of radiomic analysis in outcome prediction after adrenalectomy needs further investigation.

S, Molina CAF, Elias Jr. J, Muglia VF. Frequency of lipid-poor adrenal adenomas in magnetic resonance imaging examinations of the abdomen

Objective

To estimate the frequency of lipid-poor adenomas (LPAs) in magnetic resonance imaging (MRI) examinations.

Materials and Methods

We retrospectively investigated adrenal lesions on MRI examinations performed in a total of 2,014 patients between January 2016 and December 2017. After exclusions, the sample comprised 69 patients with 74 proven adenomas. Two readers (reader 1 and reader 2) evaluated lesion size, laterality, homogeneity, signal drop on out-of-phase (OP) images, and the signal intensity index (SII). An LPA was defined as a lesion with no signal drop on OP images and an SII < 16.5%. For 68 lesions, computed tomography (CT) scans (obtained within one year of the MRI) were also reviewed.

Results

Of the 69 patients evaluated, 42 (60.8%) were women and 27 (39.2%) were men. The mean age was 59.2 ± 14.1 years. Among the 74 confirmed adrenal adenomas evaluated, the mean lesion size was 18.5 ± 7.7 mm (range, 7.0-56.0 mm) for reader 1 and 21.0 ± 8.3 mm (range, 7.0-55.0 mm) for reader 2 (p = 0.055). On the basis of the signal drop in OP MRI sequences, both readers identified five (6.8%) of the 74 lesions as being LPAs. When determined on the basis of the SII, that frequency was three (4.0%) for reader 1 and four (5.4%) for reader 2. On CT, 21 (30.8%) of the 68 lesions evaluated were classified as LPAs.

Conclusion

The prevalence of LPA was significantly lower on MRI than on CT. That prevalence tends to be even lower when the definition of LPA relies on a quantitative analysis rather than on a qualitative (visual) analysis.

Diagnostic dilemmas: a multi-institutional retrospective analysis of adrenal incidentaloma pathology based on radiographic size

Introduction/background

Adrenal incidentalomas (AIs) are masses > 1 cm found incidentally during radiographic imaging. They are present in up to 4.4% of patients undergoing CT scan, and incidence is increasing with usage and sensitivity of cross-sectional imaging. Most result in diagnosis of adrenal cortical adenoma, questioning guidelines recommending removal of all AIs with negative functional workup. This retrospective study analyzes histological outcome based on size of non-functional adrenal masses.

Material and methods

10 years of data was analyzed from two academic institutions. Exclusion criteria included patients with positive functional workups, those who underwent adrenalectomy during nephrectomy, < 18 years, and incomplete records. AI radiologic and histologic size, histologic outcome, laterality, imaging modality, gender, and age were collected. T-test was used for comparison of continuous variables, and the two-sided Fisher’s exact or chi-square test were used to determine differences for categorical variables. Univariate analysis of each independent variable was performed using simple logistic regression.

Results

73 adrenalectomies met the above inclusion criteria. 60 were detected on CT scan, 12 on MRI, and one on ultrasound. Eight of 73 cases resulted in malignant pathology, 3 of which were adrenocortical carcinoma (ACC). Each ACC measured > 6 cm, with mean radiologic and pathologic sizes of 11.2 cm and 11.3 cm. Both radiologic and pathologic size were significant predictors of malignancy (p = 0.008 and 0.011).

Conclusions

Our results question the generally-accepted 4 cm cutoff for excision of metabolically-silent AIs. They suggest a 6 cm threshold would suffice to avoid removal of benign lesions while maintaining sensitivity for ACC.

Discriminative Capacity of CT Volumetry to Identify Autonomous Cortisol Secretion in Incidental Adrenal Adenomas

CONTEXT

Incidentally discovered adrenal adenomas are common. Assessment for possible autonomous cortisol excess (ACS) is warranted for all adrenal adenomas, given the association with increased cardiometabolic disease.

OBJECTIVE

To evaluate the discriminatory capacity of 3-dimensional volumetry on computed tomography (CT) to identify ACS.

METHODS

Two radiologists, blinded to hormonal levels, prospectively analyzed CT images of 149 adult patients with unilateral, incidentally discovered, adrenal adenomas. Diameter and volumetry of the adenoma, volumetry of the contralateral adrenal gland, and the adenoma volume-to-contralateral gland volume (AV/CV) ratio were measured. ACS was defined as cortisol ≥ 1.8 mcg/dL after 1-mg dexamethasone suppression test (DST) and a morning ACTH ≤ 15. pg/mL.

RESULTS

We observed that ACS was diagnosed in 35 (23.4%) patients. Cortisol post-DST was positively correlated with adenoma diameter and volume, and inversely correlated with contralateral adrenal gland volume. Cortisol post-DST was positively correlated with the AV/CV ratio (r = 0.46, P < 0.001) and ACTH was inversely correlated (r = -0.28, P < 0.001). The AV/CV ratio displayed the highest odds ratio (1.40; 95% CI, 1.18-1.65) and area under curve (0.91; 95% CI, 0.86-0.96) for predicting ACS. An AV/CV ratio ≥ 1 (48% of the cohort) had a sensitivity of 97% and a specificity of 70% to identify ACS.

CONCLUSION

CT volumetry of adrenal adenomas and contralateral adrenal glands has a high discriminatory capacity to identify ACS. The combination of this simple and low-cost radiological phenotyping can supplement biochemical testing to substantially improve the identification of ACS.

Management of incidental adrenal nodules: a survey of abdominal radiologists conducted by the Society of Abdominal Radiology Disease-Focused Panel on Adrenal Neoplasms

Adrenal incidentalomas are common findings discovered at abdominal CT and MRI, yet the most appropriate management remains controversial and guidelines vary. The Society of Abdominal Radiology (SAR) Disease-Focused Panel on Adrenal Neoplasms sought to determine the practice patterns of abdominal radiologists regarding the interpretation and management of adrenal incidentalomas. An electronic survey consisting of eleven multiple choice questions about adrenal incidentalomas was developed and distributed to the email list of current and past SAR members. The response rate was 11.8% (423/3581) and most respondents were academic radiologists (80.6%). The 2017 American College of Radiology White Paper was the most used guideline, yet the management of indeterminate adrenal incidentalomas was highly variable with no single management option reaching a majority. Hormonal evaluation and endocrinology consultation was most often rarely or never recommended. The results of the survey indicate wide variability in the interpretation of imaging findings and management recommendations for incidental adrenal nodules among surveyed radiologists. Further standardization of adrenal incidentaloma guidelines and education of radiologists is needed.

A Descriptive Comparative Analysis of the Surgical Management of Adrenal Tumors: The Open, Robotic, and Laparoscopic Approaches

Background

Currently, adrenalectomies are trending toward minimally invasive approach including robotic and laparoscopic surgery. We aimed to describe the clinical presentation and outcomes associated with the 3 different surgical approaches in patients who underwent adrenalectomy for adrenal mass at a single tertiary center.

Methods

A retrospective descriptive observational study was conducted to include all patients who underwent surgical interventions for adrenal gland mass between 2004 and 2019. Patients were categorized into three groups according to the interventional approach (open, robotic vs. laparoscopic adrenalectomy) and data were analyzed and compared.

Results

A total of 124 patients underwent adrenalectomies (61.3% robotic, 22.6% open, and 16.1% laparoscopic approach). Incidentally discovered adrenal mass was reported in 67% of patients, and hypertension was the most prevalent comorbidity (53%). The tendency for malignancy increased with increasing tumor size while the functioning tumors were more in the smaller tumor size. Larger tumors were more common in younger patients. The robotic approach showed shorter surgical intensive care and hospital length of stay. Patients in the open adrenalectomy group frequently presented with abdominal pain (p = 0.001), had more nonfunctional adrenal mass (p = 0.04), larger mean tumor size (p = 0.001), and were frequently operated on the right side (p = 0.03). There was no post-operative mortality; however, during follow-up, 8 patients died (3 open, 3 laparoscopic and, 2 robotic approach). The median follow-up was 746 days (range 7–5,840).

Conclusions

The study explored the three surgical adrenalectomy approaches in a dedicated center for patients with adrenal pathology. It showed that robotic adrenalectomy could be safe and effective surgical approach for patients with benign functioning adrenal tumors of a diameter &lt;6 cm. However, the choice of a surgical approach varies according to the adrenal mass presentation, patient fitness for surgery, type and sizes of the tumor, surgeon's experience, and hospital resources. Open surgery is considered the first choice for larger, ruptured adrenal tumor or malignancy. However, the recent restructuring of the surgical department resulted in selection bias in favor of the robotic surgery. Further studies are required to address the risk factors, selection criteria for appropriate management, cost, and quality of life.

Large adrenocortical adenoma with malignant features on imaging: A case report

Large adrenocortical adenomas have rarely been reported. We describe a case of a 26-year-old man who underwent an adrenalectomy for a large adrenocortical adenoma (8.6 × 7.7 cm). Although the lesion had typical malignant features on imaging, histopathological examination revealed an adrenocortical adenoma. This highlights that imaging alone may not be able to distinguish adrenocortical carcinomas from adrenal masses. In most cases, a resection should be performed for early diagnosis and management of large adrenal masses with malignant features on imaging. To our knowledge, this is the first report of a large adrenocortical adenoma diagnosed with multiple imaging investigations.

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A patient presented with abdominal and left flank pain.

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We observed an ≥8-cm lesion that appeared to be malignant on imaging.

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Histologically, the lesion was diagnosed as an adrenocortical adenoma.

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Adrenocortical adenomas with malignant imaging features must be resected.

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This will allow their early diagnosis and treatment.

Extra-adrenal phaeochromocytoma in a resource poor setting: A case report

Phaeochromocytomas are catecholamine-secreting tumors arising in the chromaffin cells of the adrenal medulla. They are a rare cause of secondary hypertension. However, catecholamine secreting tumors may also be found in the extra-adrenal sites, producing similar symptoms as the adrenal phaeochromocytoma. The extra-adrenal phaeochromocytomas, are referred to as paragangliomas (PGLs). About 75% of extra-adrenal phaeochromocytomas are intra-abdominal, mostly located in perinephric, periaortic, and bladder regions. Most phaeochromocytomas secrete excessive amount of epinephrine and norepinephrine, whereas most paragangliomas secrete only norepinephrine. The excessive secretion of these products could lead to paroxysms of symptoms that could be life threatening. Medical management is initially offered, but definitive treatment involves surgical removal of the tumor, which requires promptness on the both the clinician and the patient sides. We present a case of an extra-adrenal phaeochromocytoma in an adult male with revealing imaging of a mass surrounding the bladder. The patient was managed with both alpha- and beta-adrenergic blockers. He declined the surgery and eventually died after appearing in an acute hypertensive crisis.

Computer-assisted Reporting and Decision Support Increases Compliance with Follow-up Imaging and Hormonal Screening of Adrenal Incidentalomas

OBJECTIVE

To assess the impact of using a computer-assisted reporting and decision support (CAR/DS) tool at the radiologist point-of-care on ordering provider compliance with recommendations for adrenal incidentaloma workup.

METHOD

Abdominal CT reports describing adrenal incidentalomas (2014 - 2016) were retrospectively extracted from the radiology database. Exclusion criteria were history of cancer, suspected functioning adrenal tumor, dominant nodule size < 1 cm or ≥ 4 cm, myelolipomas, cysts, and hematomas. Multivariable logistic regression models were employed to predict follow-up imaging (FUI) and hormonal screening orders as a function of patient age and sex, nodule size, and CAR/DS use. CAR/DS reports were compared to conventional reports regarding ordering provider compliance with, frequency, and completeness of, guideline-warranted recommendations for FUI and hormonal screening of adrenal incidentalomas using Chi-square test.

RESULT

Of 174 patients (mean age 62.4; 51.1% women) with adrenal incidentalomas, 62% (108/174) received CAR/DS-based recommendations versus 38% (66/174) unassisted recommendations. CAR/DS use was an independent predictor of provider compliance both with FUI (Odds Ratio [OR]=2.47, p = 0.02) and hormonal screening (OR=2.38, p = 0.04). CAR/DS reports recommended FUI (97.2%,105/108) and hormonal screening (87.0%,94/108) more often than conventional reports (respectively, 69.7% [46/66], 3.0% [2/66], both p <0.0001). CAR/DS recommendations more frequently included instructions for FUI time, protocol, and modality than conventional reports (all p <0.001).

CONCLUSION

Ordering providers were at least twice as likely to comply with report recommendations for FUI and hormonal evaluation of adrenal incidentalomas generated using CAR/DS versus unassisted reporting. CAR/DS-directed recommendations were more adherent to guidelines than those generated without.

Development of a radiomics model to diagnose pheochromocytoma preoperatively: a multicenter study with prospective validation

BACKGROUND

Preoperative diagnosis of pheochromocytoma (PHEO) accurately impacts preoperative preparation and surgical outcome in PHEO patients. Highly reliable model to diagnose PHEO is lacking. We aimed to develop a magnetic resonance imaging (MRI)-based radiomic-clinical model to distinguish PHEO from adrenal lesions.

METHODS

In total, 305 patients with 309 adrenal lesions were included and divided into different sets. The least absolute shrinkage and selection operator (LASSO) regression model was used for data dimension reduction, feature selection, and radiomics signature building. In addition, a nomogram incorporating the obtained radiomics signature and selected clinical predictors was developed by using multivariable logistic regression analysis. The performance of the radiomic-clinical model was assessed with respect to its discrimination, calibration, and clinical usefulness.

RESULTS

Seven radiomics features were selected among the 1301 features obtained as they could differentiate PHEOs from other adrenal lesions in the training (area under the curve [AUC], 0.887), internal validation (AUC, 0.880), and external validation cohorts (AUC, 0.807). Predictors contained in the individualized prediction nomogram included the radiomics signature and symptom number (symptoms include headache, palpitation, and diaphoresis). The training set yielded an AUC of 0.893 for the nomogram, which was confirmed in the internal and external validation sets with AUCs of 0.906 and 0.844, respectively. Decision curve analyses indicated the nomogram was clinically useful. In addition, 25 patients with 25 lesions were recruited for prospective validation, which yielded an AUC of 0.917 for the nomogram.

CONCLUSION

We propose a radiomic-based nomogram incorporating clinically useful signatures as an easy-to-use, predictive and individualized tool for PHEO diagnosis.

Virtual Unenhanced Images: Qualitative and Quantitative Comparison Between Different Dual-Energy CT Scanners in a Patient and Phantom Study

MATERIALS AND METHODS

Forty-four patients with clinical contrast-enhanced abdominal examinations on each of the 3 DECT scanner types and a phantom scanned with the same protocols were included in this retrospective study. Qualitative and quantitative assessment was performed on VUE images. Quantitative evaluation included measurement of attenuation and image noise for various tissues and the phantom. Virtual unenhanced image attenuation and noise were compared between scanner types, and intrapatient interscanner reproducibility of virtual unenhanced image attenuation was calculated as the percentage of measurement pairs with an interscanner difference ≤ 10 HU. Image quality, noise, sharpness, and iodine elimination were assessed qualitatively by 2 radiologists.

RESULTS

Significant interscanner differences in VUE attenuation and noise were found in all tissues. dlDECT and rsDECT showed significantly higher VUE attenuation than dsDECT in the aorta, portal vein, and kidneys (P < 0.05). Conversely, VUE attenuation in dsDECT was significantly higher than in dlDECT/rsDECT for subcutaneous and retroperitoneal fat (both P < 0.05). A total of 91.9% (385/419) of measurements were reproducible between rsDECT and dlDECT, 70.9% (297/419) between dsDECT and rsDECT, and 66.8% (280/419) between dsDECT and dlDECT. Virtual unenhanced image attenuation in the contrast media-filled phantom cavity was 12.7 ± 4.7 HU in dlDECT, -5.3 ± 4.2 HU in rsDECT, and -4.0 ± 10.7 HU in dsDECT with significant differences between dlDECT and rsDECT/dsDECT, respectively (P < 0.05), between which attenuation was comparable in the unenhanced extraluminal phantom component (P = 0.11-0.62). Qualitatively, dsDECT yielded best iodine elimination, whereas sharpness, image noise, and overall image quality were rated higher in dlDECT and rsDECT.

CONCLUSIONS

There are significant interscanner differences in the attenuation measurements and qualitative assessment of VUE images, which should be acknowledged when using these images in patients that are being scanned on different DECT scanner types during imaging follow-up.

Risk prediction model establishment with tri-phasic CT image features for differential diagnosis of adrenal pheochromocytomas and lipid-poor adenomas: Grouping method

OBJECTIVES

The purpose of this study was to establish a risk prediction model for differential diagnosis of pheochromocytomas (PCCs) from lipid-poor adenomas (LPAs) using a grouping method based on tri-phasic CT image features.

METHODS

In this retrospective study, we enrolled patients that were assigned to a training set (136 PCCs and 183 LPAs) from two medical centers, along with an external independent validation set (30 PCCs and 54 LPAs) from another center. According to the attenuation values in unenhanced CT (CTu), the lesions were divided into three groups: group 1, 10 HU < CTu ≤ 25 HU; group 2, 25 HU < CTu ≤ 40 HU; and group 3, CTu > 40 HU. Quantitative and qualitative CT imaging features were calculated and evaluated. Univariate, ROC, and binary logistic regression analyses were applied to compare these features.

RESULTS

Cystic degeneration, CTu, and the peak value of enhancement in the arterial and venous phase (DEpeak) were independent risk factors for differential diagnosis of adrenal PCCs from LPAs. In all subjects (groups 1, 2, and 3), the model formula for the differentiation of PCCs was as follows: Y = -7.709 + 3.617*(cystic degeneration) + 0.175*(CTu ≥ 35.55 HU) + 0.068*(DEpeak ≥ 51.35 HU). ROC curves were drawn with an AUC of 0.95 (95% CI: 0.927-0.973) in the training set and 0.91 (95% CI: 0.860-0.929) in the external validation set.

CONCLUSION

A reliable and practical prediction model for differential diagnosis of adrenal PCCs and LPAs was established using a grouping method.

Adrenal Schwannoma in an Elderly Man: A Case Report and Literature Review

Schwannoma is a common mesenchymal neoplasm; however, adrenal schwannoma is rare, and it is frequently misdiagnosed as adrenal cortical adenoma. We herein report a 91-year-old Japanese man with right adrenal schwannoma that was pathologically diagnosed after adrenalectomy. To our knowledge, this is the first case of adrenal schwannoma in the oldest patient and with the longest follow-up period reported, including radiological images from 10 years earlier.

The ADRENAL score: A comprehensive scoring system for standardized evaluation of adrenal tumor

OBJECTIVES

To propose an original and standardized scoring system to quantify the functional and anatomical characteristics of adrenal tumor.

MATERIALS AND METHODS

Four groups of consecutive adrenalectomies (n = 458) with heterogeneity in tumor characteristics and surgical approaches, including 212 laparoscopic cases (Group 1) and 105 robotic cases (Group 2) from The First Affiliated Hospital of Nanchang University, 28 robotic cases from Temple University Hospital (Group 3) and 113 laparoscopic cases from The First Affiliated Hospital of Guangxi Medical University (Group 4). All patients were followed up for 4.5 to 5.5 years. Six parameters including functional status or suspicion of malignancy, tumor size, relationship to adjacent organs, intratumoral enhancement on CT, nearness of the tumor to major vessels and body mass index were assessed and scored on a 0, 1 and 2 points scale. Correlation between the sum of the 6 scores and tumor laterality (ADRENAL score) verse operative time (OT), estimated blood loss (EBL), perioperative complications, transfusion, conversion and length of hospital stay was analyzed.

RESULTS

ADRENAL score was a strong predictor of both OT and EBL in all four groups (p < 0.05 for all tests). In Group 2 and 4, higher ADRENAL score seemed to correlate with longer hospital stay. No statistically significant correlation between ADRENAL score and complication, transfusion or conversion was noted yet.

CONCLUSIONS

ADRENAL score appears to be a valid predictor of surgical outcomes. It may provide a common reference for adrenal surgery training program, preoperative risk assessment and stratified comparative analysis of adrenal surgeries via different techniques and approaches.

Disorders of the adrenal cortex: Genetic and molecular aspects

Adrenal cortex produces glucocorticoids, mineralocorticoids and adrenal androgens which are essential for life, supporting balance, immune response and sexual maturation. Adrenocortical tumors and hyperplasias are a heterogenous group of adrenal disorders and they can be either sporadic or familial. Adrenocortical cancer is a rare and aggressive malignancy, and it is associated with poor prognosis. With the advance of next-generation sequencing technologies and improvement of genomic data analysis over the past decade, various genetic defects, either from germline or somatic origin, have been unraveled, improving diagnosis and treatment of numerous genetic disorders, including adrenocortical diseases. This review gives an overview of disorders associated with the adrenal cortex, the genetic factors of these disorders and their molecular implications.

Adrenal wash-out CT: moderate diagnostic value in distinguishing benign from malignant adrenal masses

OBJECTIVE

Reliable results of wash-out CT in the diagnostic workup of adrenal incidentalomas are scarce. Thus, we evaluated the diagnostic accuracy of delayed wash-out CT and determined thresholds to accurately differentiate adrenal masses.

DESIGN

Retrospective, single-center cohort study including 216 patients with 252 adrenal lesions who underwent delayed wash-out CT. Definitive diagnoses based on histopathology (n = 92) or comprehensive follow-up.

METHODS

Size, average attenuation values of the adrenal lesions in all CT scan phases, and absolute and relative percentage wash-out (APW/RPW) were determined by an expert radiologist blinded for clinical data. Adrenal lesions with unenhanced attenuation values >10 Hounsfield units (HU) built a subgroup (n = 142). Diagnostic accuracy was calculated.

RESULTS

The study group consisted of 171 adenomas, 32 other benign tumors, 11 pheochromocytomas, 9 adrenocortical carcinomas, and 29 other malignant tumors. All (potentially) malignant and 46% of benign lesions showed unenhanced attenuation values >10 HU. In this most relevant subgroup, the established thresholds of 60% for APW and 40% for RPW misclassified 35.9 and 35.2% of the masses, respectively. When we applied optimized cutoffs (APW >83%; RPW >58%) and excluded pheochromocytomas, we missed only one malignant tumor by APW and none by RPW. However, only 11 and 15% of the benign tumors were correctly identified.

CONCLUSIONS

Wash-out CT with the established thresholds for APW and RPW is insufficient to reliably diagnose adrenal masses. Using the proposed cutoff of 58% for RPW, malignant tumors will be correctly identified, but the added value is limited, namely 15% of patients with benign tumors can be prevented from additional imaging or even unnecessary surgery.

Frequently asked questions and answers (if any) in patients with adrenal incidentaloma

PURPOSE

Adrenal incidentalomas (AIs) are incidentally discovered adrenal masses, during an imaging study undertaken for other reasons than the suspicion of adrenal disease. Their management is not a minor concern for patients and health-care related costs, since their increasing prevalence in the aging population. The exclusion of malignancy is the first question to attempt, then a careful evaluation of adrenal hormones is suggested. Surgery should be considered in case of overt secretion (primary aldosteronism, adrenal Cushing's Syndrome or pheochromocytoma), however the management of subclinical secretion is still a matter of debate.

METHODS

The aim of the present narrative review is to offer a practical guidance regarding the management of AI, by providing evidence-based answers to frequently asked questions.

CONCLUSION

The clinical experience is of utmost importance: a personalized diagnostic-therapeutic approach, based upon multidisciplinary discussion, is suggested.

ACR Appropriateness Criteria® Adrenal Mass Evaluation: 2021 Update

The appropriate evaluation of adrenal masses is strongly dependent on the clinical circumstances in which it is discovered. Adrenal incidentalomas are masses that are discovered on imaging studies that have been obtained for purposes other than adrenal disease. Although the vast majority of adrenal incidentalomas are benign, further radiological and biochemical evaluation of these lesions is important to arrive at a specific diagnosis. Patients with a history of malignancy or symptoms of excess hormone require different imaging evaluations than patients with incidentalomas. This document reviews imaging approaches to adrenal masses and the various modalities utilized in evaluation of adrenal lesions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Draft of the clinical practice guidelines “Adrenal incidentaloma”

The wider application and technical improvement of abdominal imaging procedures in recent years has led to an increasingly frequent detection of adrenal gland masses — adrenal incidentaloma, which have become a common clinical problem and need to be investigated for evidence of hormonal hypersecretion and/or malignancy. Clinical guidelines are the main working tool of a practicing physician. Laconic, structured information about a specific nosology, methods of its diagnosis and treatment, based on the principles of evidence-based medicine, make it possible to give answers to questions in a short time, to achieve maximum efficiency and personalization of treatment. These clinical guidelines include data on the prevalence, etiology, radiological features and assessment of hormonal status of adrenal incidentalomas. In addition, this clinical practice guideline provides information on indications for surgery, postoperative rehabilitation and follow-up.

Adrenal Nodules Detected at Staging CT in Patients with Resectable Gastric Cancers Have a Low Incidence of Malignancy

Background Guidelines recommending additional imaging for adrenal nodules lack relevant epidemiologic evidence. Purpose To measure the prevalence of adrenal nodules detected at staging CT in patients with potentially resectable gastric cancer and the proportion of patients with malignant nodules among them. Materials and Methods This retrospective study included 10 250 consecutive patients (median age, 63 years; interquartile range, 53-71 years; 6884 men) who underwent staging CT and had potentially resectable gastric cancer in a tertiary center (May 2003 to December 2018). All 10 250 CT studies were retrospectively reviewed, and patients with adrenal nodules (or thickening ≥10 mm) were identified to measure the prevalence of adrenal nodules. Among patients with adrenal nodules, the per-patient proportions of malignant nodules, adrenal metastasis from gastric cancer, and additional adrenal examinations were measured. A secondary analysis was performed by using data from the original CT reports. The same metrics that were used in the retrospective review were assessed. Results The prevalence of adrenal nodules was 4.5% (95% CI: 4.1, 4.9; 462 of 10 250). The proportions of malignant nodules and adrenal metastasis from gastric cancer were 0.4% ( 95% CI: 0.1, 1.6; two of 462) and 0% (95% CI: 0.0, 0.8; 0 of 462), respectively. A total of 27% of the patients (95% CI: 23, 31; 123 of 462) underwent additional adrenal examination. According to original CT reports, the prevalence of adrenal nodules and the proportions of malignant nodules, adrenal metastases from gastric cancer, and additional adrenal examination were 2.7% (95% CI: 2.4, 3.0; 272 of 10 250), 0.7% (95% CI: 0.1, 2.6; two of 272), 0% (95% CI: 0.0, 1.4; 0 of 272), and 42.6% (95% CI: 36.7, 48.8; 116 of 272), respectively. Conclusion Although adrenal nodules were detected frequently on staging CT images of patients with otherwise resectable gastric cancer, these nodules were rarely malignant. ©RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Baumgarten in this issue.

Metabolic Subtyping of Adrenal Tumors: Prospective Multi-Center Cohort Study in Korea

BACKGROUND

Conventional diagnostic approaches for adrenal tumors require multi-step processes, including imaging studies and dynamic hormone tests. Therefore, this study aimed to discriminate adrenal tumors from a single blood sample based on the combination of liquid chromatography-mass spectrometry (LC-MS) and machine learning algorithms in serum profiling of adrenal steroids.

METHODS

The LC-MS-based steroid profiling was applied to serum samples obtained from patients with nonfunctioning adenoma (NFA, n=73), Cushing's syndrome (CS, n=30), and primary aldosteronism (PA, n=40) in a prospective multicenter study of adrenal disease. The decision tree (DT), random forest (RF), and extreme gradient boost (XGBoost) were performed to categorize the subtypes of adrenal tumors.

RESULTS

The CS group showed higher serum levels of 11-deoxycortisol than the NFA group, and increased levels of tetrahydrocortisone (THE), 20α-dihydrocortisol, and 6β-hydroxycortisol were found in the PA group. However, the CS group showed lower levels of dehydroepiandrosterone (DHEA) and its sulfate derivative (DHEA-S) than both the NFA and PA groups. Patients with PA expressed higher serum 18-hydroxycortisol and DHEA but lower THE than NFA patients. The balanced accuracies of DT, RF, and XGBoost for classifying each type were 78%, 96%, and 97%, respectively. In receiver operating characteristics (ROC) analysis for CS, XGBoost, and RF showed a significantly greater diagnostic power than the DT. However, in ROC analysis for PA, only RF exhibited better diagnostic performance than DT.

CONCLUSION

The combination of LC-MS-based steroid profiling with machine learning algorithms could be a promising one-step diagnostic approach for the classification of adrenal tumor subtypes.

Machine learning-based texture analysis for differentiation of radiologically indeterminate small adrenal tumors on adrenal protocol CT scans

GOAL

To evaluate the ability of radiomic feature extraction and a machine learning algorithm to differentiate between benign and malignant indeterminate adrenal lesions on contrast-enhanced computed tomography (CT) studies.

BACKGROUND

Adrenal "incidentalomas" are adrenal lesions that are accidentally discovered during workup not related to the adrenal glands; they have an incidence as high as 5%. Small adrenal incidentalomas (< 4 cm) with high attenuation values on pre-contrast CT(> 10 HU) need further evaluation to calculate the absolute percentage of washout (APW). If the APW is < 60%, these lesions are considered non-adenomas and commonly classified as indeterminate adrenal lesions. Further workup for indeterminate lesions includes more complicated and expensive radiological studies or invasive procedures like biopsy or surgical resection.

METHODS

We searched our institutional database for indeterminate adrenal lesions with the following characteristics: < 4 cm, pre-attenuation value > 10 HU, and APW < 60%. Exclusion criteria included pheochromocytoma and no histopathological examination. CT images were converted to Nifti format, and adrenal tumors were segmented using Amira software. Radiomic features from the adrenal mask were extracted using PyRadiomics software after removing redundant features (highly pairwise correlated features and low-variance features) using recursive feature extraction to select the final discriminative set of features. Lastly, the final features were used to build a binary classification model using a random forest algorithm, which was validated and tested using leave-one-out cross-validation, confusion matrix, and receiver operating characteristic curve.

RESULTS

We found 40 indeterminate adrenal lesions (21 benign and 19 malignant). Feature extraction resulted in 3947 features, which reduced down to 62 features after removing redundancies. Recursive feature elimination resulted in the following top 4 discriminative features: gray-level size zone matrix-derived size zone non-uniformity from pre-contrast and delayed phases, gray-level dependency matrix-derived large dependence high gray-level emphasis from venous-phase, and gray-level co-occurrence matrix-derived cluster shade from delayed-phase. A binary classification model with leave-one-out cross-validation showed AUC = 0.85, sensitivity = 84.2%, and specificity = 71.4%.

CONCLUSION

Machine learning and radiomic features extraction can differentiate between benign and malignant indeterminate adrenal tumors and can be used to direct further workup with high sensitivity and specificity.

A Rare Presentation of Adrenocortical Carcinoma

An adrenal incidentaloma is a mass found incidentally on radiological imaging performed for other reasons. The prevalence of these incidentalomas increases with age, and they all must be evaluated to determine if they are benign or malignant and if they are functioning or non-functioning. A 71-year-old female presented with sub-acute bilateral lower limb pitting edema and dyspnoea. Imaging showed an 8 cm smoothly defined heterogeneous right adrenal mass and a number of low attenuation lesions throughout the liver. This case report describes a rare presentation of adrenocortical carcinoma due to an adrenal incidentaloma identified on imaging in a patient presenting with bilateral lower limb edema. The laboratory and imaging evaluation of these incidentalomas are also discussed.

An Adrenocortical Carcinoma Evolving After Nine Years of Latency From a Small Adrenal Incidentaloma

Adrenal incidentalomas (AIs) are common incidental findings in medical practice with clinical significance. Although most AIs are nonsecretory and nonmalignant, they require a short course of follow-up over one to two years to rule out malignancy or hormonal secretion according to clinical practice guidelines. However, this can result in some adrenocortical carcinomas (ACCs) being missed if they transform at a later stage or evolve slowly. Here, we report one such case of an AI, which although remained indolent, eventually transformed into an ACC many years after the initial detection.

Differentiation of lipid-poor adenoma from pheochromocytoma on biphasic contrast-enhanced CT

PURPOSE

To evaluate the diagnostic performance of biphasic contrast-enhanced CT in differentiation of lipid-poor adenomas from pheochromocytomas.

METHODS

129 patients with 132 lipid-poor adenomas and 93 patients with 97 pheochromocytomas confirmed by pathology were included in this retrospective study. Patients underwent unenhanced abdominal CT scan followed by arterial and venous phase. Quantitative and qualitative imaging features were compared between the two groups using univariate analysis. Risk factors for pheochromocytomas were evaluated by multivariate logistic regression analysis and a diagnostic scoring model was established based on odd ratio (OR) of the risk factors.

RESULTS

Pheochromocytomas were larger and showed cystic degeneration more frequently compared with lipid-poor adenomas (p < 0.01). No significant difference was found in peak enhancement phase between the two groups (p = 0.348). Attenuation values on unenhanced phase (CTU), arterial phase (CTA), and venous phase (CTV) of pheochromocytomas were significantly higher than that of lipid-poor adenomas while enhancement ratio on arterial and venous phase (ERA, ERV) of pheochromocytomas was significantly lower than that of lipid-poor adenomas (all p < 0.05). Multivariate analysis revealed lesion size > 29 mm (OR: 5.74; 95% CI 2.51-13.16; p < 0.001), CTA > 81 HU (OR: 2.54; 95% CI 1.04-6.17; p = 0.04), CTV > 97 HU (OR: 11.19; 95% CI 3.21-38.97; p < 0.001), ERV ≤ 1.5 (OR: 20.23; 95% CI 6.30-64.87; p < 0.001), and the presence of cystic degeneration (OR: 6.22, 95% CI 1.74-22.25; p = 0.005) were risk factors for pheochromocytomas. The diagnostic scoring model yielded an area under the curve (AUC) of 0.911.

CONCLUSIONS

Biphasic contrast-enhanced CT showed good diagnostic performance in differentiation of lipid-poor adenomas from pheochromocytomas.

Can abdominal CT features predict autonomous cortisol secretion in patients with adrenal nodules?

PURPOSE

To determine if CT features of adrenal nodules and of the remainder of the abdomen can predict autonomous cortisol secretion (ACH) in patients with adrenal nodules, and to identify a nodule size threshold below which ACH is unlikely.

METHODS

Retrospective review of adult patients with adrenal nodules who underwent CT of abdomen and 1-mg Dexamethasone suppression test within 1 year of each other. Patients were considered to have no ACH if serum cortisol was ≤ 1.8 µg/dL after the 1-mg dexamethasone suppression test and to have possible or definite autonomous cortisol secretion if serum cortisol was > 1.8 µg/dL. The following CT features were assessed: Adrenal nodule length, nodule width, unenhanced nodule attenuation, contralateral adrenal gland thickness, visceral and subcutaneous adipose tissue area, skeletal muscle area and density, and unenhanced liver attenuation.

RESULTS

29 patients had no autonomous cortisol secretion and 29 patients had possible or definite autonomous cortisol secretion. Nodule length and width were the only two variables that significantly differed between patients with nonfunctional nodules and those with possibly or definitely functional nodules. Using a threshold nodule length of 1.5 cm, the sensitivity and specificity for predicting possible or definite autonomous cortisol secretion was 93.1% and 37.9%, respectively.

CONCLUSION

Autonomous cortisol secretion in patients with adrenal nodules correlates with increasing nodule size. A nodule length threshold of 1.5 cm provides 93.1% sensitivity for predicting possible or definite ACH based on the 1-mg Dexamethasone suppression test.

How to Differentiate Benign from Malignant Adrenocortical Tumors?

Simple Summary

Adrenocortical carcinoma is a rare cancer with a poor prognosis. Adrenal tumors are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance to determine the appropriate treatment and follow-up strategy. This review summarizes the current diagnostic strategies and challenges to distinguish benign from malignant adrenal lesions. We will focus both on radiological and biochemical assessments, enabling diagnosis of the adrenal lesion preoperatively, and on histopathological and a wide variety of molecular assessments that can be done after surgical removal of the adrenal lesion. Furthermore, new non-invasive strategies such as liquid biopsies, in which blood samples are used to study circulating tumor cells, tumor DNA and microRNA, will be addressed in this review.

Abstract

Adrenocortical carcinoma (ACC) is a rare cancer with a poor prognosis. Adrenal incidentalomas are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance considering the large differences in clinical behavior requiring different strategies. Diagnosis of ACC starts with a thorough physical examination, biochemical evaluation, and imaging. Computed tomography is the first-level imaging modality in adrenal tumors, with tumor size and Hounsfield units being important features for determining malignancy. New developments include the use of urine metabolomics, also enabling discrimination of ACC from adenomas preoperatively. Postoperatively, the Weiss score is used for diagnosis of ACC, consisting of nine histopathological criteria. Due to known limitations as interobserver variability and lack of accuracy in borderline cases, much effort has been put into new tools to diagnose ACC. Novel developments vary from immunohistochemical markers and pathological scores, to markers at the level of DNA, methylome, chromosome, or microRNA. Molecular studies have provided insights into the most promising and most frequent alterations in ACC. The use of liquid biopsies for diagnosis of ACC is studied, although in a small number of patients, requiring further investigation. In this review, current diagnostic modalities and challenges in ACC will be addressed.

Unenhanced Dual-Layer Spectral-Detector CT for Characterizing Indeterminate Adrenal Lesions

Background Unenhanced dual-layer spectral-detector CT may facilitate adrenal lesion characterization; however, no studies have evaluated its incremental diagnostic yield for indeterminate lesions (unenhanced attenuation >10 HU) in comparison to that with conventional unenhanced CT. Purpose To determine whether spectral attenuation analysis improves characterization of lipid-poor adrenal adenomas from nonadenomas compared to that with mean attenuation and histogram analysis of conventional CT images. Materials and Methods This retrospective study included patients with indeterminate adrenal lesions who underwent unenhanced dual-layer spectral-detector CT between March 2018 and June 2020. Mean attenuation on conventional 120-kVp images (HU_conv), histogram-based percentage negative pixels (proportion of all pixels <0 HU) on conventional 120-kVp images, and mean attenuation on virtual monoenergetic images (VMIs) at 40-140 keV were measured for each lesion. The attenuation difference between virtual monoenergetic 140- and 40-keV images (ΔHU; ie, Hounsfield unit at 140 keV - Hounsfield unit at 40 keV) and ΔHU indexed with HU_conv (ΔHU index; ie, ΔHU/HU_conv × 100) were calculated. Conventional and virtual monoenergetic imaging parameters were compared between lipid-poor adenomas and nonadenomas by using the Mann-Whitney U test. Receiver operating characteristic analysis was performed to determine the sensitivity for attaining at least 95% specificity in characterizing adenomas from nonadenomas; sensitivity was compared by using the McNemar test. Results A total of 232 patients (mean age ± standard deviation, 67 years ± 11; 145 men) with 129 lipid-poor adenomas and 103 nonadenomas were evaluated. HU_conv and mean attenuation on VMIs at 40-140 keV were lower and the percentage negative pixels, ΔHU, and ΔHU index higher in lipid-poor adenomas than in nonadenomas (P < .001 for all). Attenuation differences between adenomas and nonadenomas on VMIs were maximal at 40 keV (23 HU at 40 keV vs 5 HU at 140 keV). The highest sensitivities for differentiating adenomas and nonadenomas were achieved for virtual monoenergetic ΔHU index (77% [99 of 129 adenomas]), attenuation on 40-keV images (71% [91 of 129 adenomas]), and ΔHU (67% [87 of 129 adenomas]) compared to HU_conv (35% [45 of 129 adenomas]) and percentage negative pixels (30% [39 of 129 adenomas]) (P < .001 for all; specificity, 95% [98 of 103 nonadenomas]). Conclusion Spectral attenuation analysis enabled differentiation of lipid-poor adenomas from nonadenomas with higher sensitivity than mean attenuation or histogram analysis of conventional CT images. © RSNA, 2021 Online supplemental material is available for this article.

Adrenal biopsy, as a diagnostic method, is associated with decreased overall survival in patients with T1/T2 adrenocortical carcinoma: A propensity score-matched analysis

INTRODUCTION

The standard diagnosis for adrenocortical carcinoma (ACC) is clinical diagnosis (CD) based on radiographic and biochemical studies. Biopsy diagnosis (BD) is seldom required for the suspicion of secondary malignancy. We aim to study the impact of BD in the context of underlying T1/T2 ACC on overall survival (OS) compared with CD.

METHODS

National Cancer Database (NCDB) for endocrine malignancies was utilized. Only patients with non-metastatic ACC, whose method of diagnosis and local disease extension were reported, and received a surgical adrenalectomy with curative intent were included. Patients were divided by disease stage into T1/T2, T3, and T4 groups. A propensity score match was applied to those with T1/T2 disease who received CD versus BD and the Kaplan-Meier method was used to compare OS.

RESULTS

In total, 4000 patients with ACC were reported in the database, 1410 met selection criteria. Eight hundred and thirty patients had T1/T2, 365 had T3, and 162 had T4 ACC. Of patients with T1/T2 ACC, 742 (89.4%) received CD versus 88 (11.6%) with BD. A propensity score was calculated per a multivariable regression model with 79 patients matched from each group. Exact matching was applied for margin status and adjuvant therapies. Kaplan-Meier analysis showed a significant difference in median OS between CD versus BD patients in the matched data set (103.89 ± 15.65 vs. 54.93 ± 8.22 months; p = 0.001). In all comers, patients with T1/T2 ACC and BD had comparable median OS to that of patients with T3 ACC (52.21 ± 9.69 vs. 36.01 ± 3.33 months; p = 0.446).

CONCLUSION

BD in T1/T2 ACC could be associated with disease upstaging and worse OS outcomes.

Virtual or real: lifelike cinematic rendering of adrenal tumors

The adrenal gland is small in size and hidden in location. Adrenal tumors are relatively difficult to diagnose due to the wide variety of tumors and partial overlap of image features. Cinematic rendering (CR) is a novel, three-dimensional post-processing technology that simulates how light propagates in the real world, providing high-resolution visualizations that truly present subtle anatomical details. We retrospectively collected a series of pathologically confirmed adrenal tumor cases, raw data was introduced into the post-processing workstation, and different tools and templates of CR software were used for reconstruction and rendering. Compared with traditional black and white two-dimensional images and three-dimensional volume rendering (VR) images, CR images were more colorful, layered, and closer to the truth. CR has potential in diagnosing and preoperative planning of adrenal tumors, allowing vivid and realistic visualization of tumor location, morphology, different components (solid, cystic, fat, calcification, etc.), the pattern of enhancement, and the relationship with surrounding tissues and organs.

Synchronous gastric cancer and primary lymphoma of right adrenal gland: a case report

This report presents an extremely rare case of synchronous gastric cancer and primary adrenal diffuse large B-cell lymphoma (DLBCL). An 82-year-old man underwent computed tomography, which revealed a heterogeneous appearing and hypodense adrenal mass and a gastric mass with no enlarged lymph nodes in the neck, mediastinum, abdomen, and inguinal region. Upper gastrointestinal endoscopy revealed a protruding gastric tumor. The specimens obtained from endoscopic biopsy were histologically confirmed to be adenocarcinoma. The hormonal findings eliminated functional adrenal tumor. The patient underwent distal gastrectomy with regional lymph node resection for gastric cancer and incisional biopsy of the adrenal mass. Based on the pathological findings, diagnoses of mixed mucinous and tubular adenocarcinomas of the stomach and adrenal DLBCL were confirmed. Postoperation, the patient received rituximab combined with low-dose doxorubicin, cyclophosphamide, vincristine, and prednisone (R-miniCHOP). Six courses of R-miniCHOP were planned, but were completed in only one course at the patient’s request. The patient died 2 months after surgery.

A Clinical Challenge: Endocrine and Imaging Investigations of Adrenal Masses

Incidentalomas are reported in 3%-4% of patients who undergo abdominal anatomic imaging, making adrenal mass evaluation a common occurrence. An adrenal mass can be caused by a variety of pathologies, such as benign cortical and medullary tumors, malignant tumors (primary or secondary), cysts, hyperplasia, hemorrhage, or more rarely infection/inflammation processes. Functioning tumors usually have increased hormonal production but they are less common. Regardless of their functional status, some tumors have the potential to behave aggressively. Anatomic and functional imaging together with biologic evaluation play a vital role in adrenal pathology subtyping. Most patients are initially evaluated by CT or MRI, which allows for tumor characterization (to a certain extent) and can rule out malignant behavior based on the absence of tumor growth during longitudinal follow-up. In the remaining patients for whom CT or MRI fail to characterize the pathogenesis of adrenal tumors, the use of specialized molecular imaging techniques should be performed after hormonal screening. This review emphasizes well-established and emerging nuclear medicine imaging modalities and describes their use across various clinical scenarios.

Steroidogenesis in patients with adrenal incidentalomas: Extended steroid profile measured by liquid chromatography-mass spectrometry after ACTH stimulation and dexamethasone suppression

OBJECTIVE

Describe the secretion and profile of adrenal steroids in patients with adrenal incidentalomas compared to control subjects.

DESIGN, SETTING AND PARTICIPANTS

A prospective study, 73 patients with adrenal incidentalomas, 21 bilateral and 52 unilateral and 34 matched controls in University Hospital.

METHODS

Collect fasting blood sample before and 60 min after ACTH test (250 µg IV). One week later, perform overnight 1 mg dexamethasone test. The following steroids were measured by liquid chromatography-mass spectrometry (LC-MS): pregnenolone, 17-OH pregnenolone, 17-OH progesterone, 11-deoxycorticosterone, 11-deoxyortisol, 21-deoxycortisol, corticosterone, cortisol, androstenedione and aldosterone.

RESULTS

Mean baseline serum cortisol was higher in incidentalomas, bilateral 361 ± 124, (range 143-665) nmol/L,(p < .0001), unilateral 268 ± 89 3.2 (range 98-507) nmol/L (p < .019) compared to controls 207 ± 100 (range 72-502) nmol/L. ACTH stimulation showed significantly higher levels in bilateral and unilateral cases compared to controls. After dexamethasone, mean serum cortisol levels suppressed in bilaterals 89 ± 69 (range 30-3) nmol/L (p < .0001), 58 ± 52 (range 16-323) nmol/L in unilateral (p < .01) compared to 26 ± 9 (range 7-46) nmol/L in controls. Mean baseline serum corticosterone was higher in bilateral 9.3 ± 4.8 (range 2.4-18.4) nmol/L (p < .005) and unilateral 7.3 ± 5.7 (range 0.1-30.3) nmol/L (p < .01) compared to controls 4.2 ± 2.4 (range 1.1-10.2) nmol/L, after ACTH stimulation significantly increased to higher levels in bilateral (p < .0002) and unilateral cases (p < .044) compared to controls. After dexamethasone, mean levels were 2.5 ± 2.6 (range 0.5-12.5) nmol/L in bilateral (p < .0006), 1.5 ± 1.6 (range 0.3-9.3) nmol/L in unilateral (p < .09) and 0.75 ± 0.46 (range 0.1-2.1) nmol/L in controls. Mean baseline serum 11-deoxycorticosterone (DOC) was higher in bilaterals 0.32 ± 0.23 (range 0.08-1.1) nmol/L (p < .03) compared to controls 0.15 ± 0.21 (range 0.08-1.1) nmol/L. ACTH stimulation increased levels to 3.27 ± 1.72 (range 0.5-7.4) nmol/L in bilateral cases compared to controls 1.369 ± 1.53 (range 0.1-7.1) nmol/L (p < .0001). Dexamethasone decreased levels to baseline (p ns). There were significant differences in serum 21-deoxycortisol (p < .0002) and serum pregnenolone (p < .004) only after ACTH stimulation.

CONCLUSIONS

There is increased activity in several steroid biosynthesis pathways and higher steroid levels in bilateral compared to unilateral cases and evidence of hypercortisolism in 30% unilateral and 62% of bilateral incidentalomas.

Radiology report language positively influences adrenal incidentaloma guideline adherence

BACKGROUND

Adrenal incidentalomas are common radiographic findings. Guidelines recommend biochemical and radiographic surveillance of adrenal incidentalomas. We investigated if patients were appropriately referred for outpatient evaluation.

METHODS

Retrospective chart review was performed to identify patients with adrenal masses on imaging between November 7, 2016 and November 7, 2017. Demographic information, medical history, and outpatient referral information was collected.

RESULTS

11,723 computed tomography (CT) scans of the chest and/or abdomen/pelvis were performed. 246 patients were noted to have adrenal incidentalomas and met inclusion criteria. The CT report recommended follow-up in 63/246 cases (25.6%). 38/246 (15.4%) patients were referred for evaluation. Age, adrenal nodule size, and type of evaluating provider did not affect referral. A radiology report recommending follow-up was associated with increased referral rate (OR 5.441, 95% CI: 2.491-11.887).

CONCLUSION

There was low outpatient referral for adrenal incidentalomas. Language in the radiology report significantly influenced referral rates and may be an important resource for improving guideline adherence.