Images of pheochromocytoma in adrenal glands

Incidental detection of purely cystic pheochromocytoma in a young adult presenting with lower urinary tract infection

Pheochromocytoma is a rare neuroendocrine tumor arising from adrenal medulla. Patients usually show classic triad of headache, palpitations and diaphoresis along with persistent or paroxysmal hypertension. Majority of the tumors are solid or mixed solid and cystic. But purely cystic variant is extremely rare with few cases reports available in the published literature. We report a case of purely cystic pheochromocytoma in a male in 30s who presented to our hospital for unrelated symptom of recurrent burning micturition. He was evaluated for causes of recurrent UTI which revealed incidental right adrenal cyst. The patient's blood pressure was raised on clinical examination and imaging showed simple adrenal cyst without solid component or septations. Suspecting possibility of pheochromocytoma, biochemical analysis was done which revealed elevated 24-hour urinary metanephrine. The diagnosis of cystic pheochromocytoma was made. Adrenalectomy was performed showing cystic lesion in the right adrenal region. Histopathology and immunohistochemistry revealed pheochromocytoma with cystic degeneration. Patient's hypertension resolved during the follow up. In conclusion, purely cystic pheochromocytoma must be considered as differential for adrenal cystic lesions, especially when atypical features are present.

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.

THE ROLE OF TUMOR-SEEKING RADIOPHARMACEUTICALS IN THE DIAGNOSIS AND MANAGEMENT OF ADRENAL TUMORS

Context

The variety of tumor-seeking radiopharmaceuticals, which are currently in clinical use, may have a potential role as imaging agents for adrenal gland tumors, due to physiological characteristics of this organ.

Objective

The purpose of this study was to evaluate the diagnostic potential of ^99mTc-HYNIC-TOC, ^99mTc(V)-DMSA, and ^99mTc-MIBI in the assessment of adrenal tumors, by correlating with imaging findings and histopathologic results.

Design

The research is designed as a cross-sectional prospective study.

Patients and method

The study included 50 patients with adrenal tumors (19 hormone-secreting and 31 nonfunctioning) and 23 controls without adrenal involvement. In all patients, single-photon emission computed tomography (SPECT) was performed, using qualitative and semiquantitative analysis. The tumor to non-tumor tracer uptake was conducted by using a region-of-interest technique. Adrenal to background (A/B) ratio was calculated in all cases.

Results

^99mTc-HYNIC-TOC scintigraphy showed a high statistical significance between A/B ratios, while other two tracers resulted in a lower sensitivity, specificity and accuracy. Futhermore, ^99mTc-HYNIC-TOC could have a high diagnostic yield to detect adrenal tumors (the receiver-operating-characteristic curve analysis, A/B ratio cut-off value of 8.40).

Conclusion

A semiquantitative SPECT analysis showed that ^99mTc-HYNIC-TOC is a highly sensitive tumor-seeking agent for the accurate localization of adrenal tumors.

Mimics, pitfalls, and misdiagnoses of adrenal masses on CT and MRI

Due to the widespread use of imaging, incidental adrenal masses are commonly encountered. A number of pitfalls can result in misdiagnosis of these lesions, including inappropriate choice of imaging technique, presence of pseudolesions, and overlap of imaging features of different adrenal lesions. This article explores the potential pitfalls in imaging of the adrenal glands, on computed tomography and magnetic resonance imaging, that can lead to misinterpretation. Clues to correct diagnoses are provided to evade potential misinterpretation.

Characteristic CT features of pheochromocytomas - probability model calculation tool based on a multicentric study

OBJECTIVES

The aim of the study was to evaluate the CT features of adrenal tumors in an effort to identify features specific to pheochromocytomas and second, to define a feasible probability calculation model.

METHODS

This multicentric retrospective study included patients from the period 2003 to 2017 with an appropriate CT examination and a histological diagnosis of an adrenal adenoma, pheochromocytoma, adrenocortical carcinoma, or metastasis. In total, 346 patients were suitable for the CT image analysis, which included evaluation of the largest diameter, the shape of the lesion, the presence of central necrosis and its margins, and the presence of an enhancing peripheral rim ("ring sign").

RESULTS

Pheochromocytomas have a significantly more spherical shape (P<0.001), whereas an elliptical shape significantly reduces the probability of a pheochromocytoma (odds ratio = 0.015), as does another shape (odds ratio = 0.006). A "ring sign" is also more frequent in pheochromocytomas compared to other adrenal tumors (P=0.001, odds ratio = 6.49). A sharp necrosis also increases the probability of a pheochromocytoma more than unsharp necrosis (odds ratio 231.6 vs. 20.2). The probability calculation model created on the basis of the results confirms a high sensitivity and specificity (80% and 95%).

CONCLUSION

This study confirms the value of anatomical features in the assessment of adrenal masses with the ability to significantly improve the identification of pheochromocytomas. Advanced assessment of the tumor shape was defined and a original comprehensive calculating tool of the pheochromocytoma probability was created on the basis of the results presented here and could be used in clinical routine.

Bilaterally enlarged adrenal glands without obvious cause: need for a multidisciplinary diagnostic work-up

Bilateral enlarged adrenal glands are rare, and as diagnostic delay may have serious consequences for the patient, we recommend a multidisciplinary approach of specialists in the field of endocrinology, oncology, radiology, and clinical chemistry prior to the start of the diagnostic work‐up.

Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy

The topic of pheochromocytomas is becoming increasingly popular as a result of major advances in different medical fields, including laboratory diagnosis, genetics, therapy, and particularly in novel advances in imaging techniques. The present review article discusses current clinical, biochemical, genetic and histopathological aspects of the diagnosis of pheochromocytomas and planning of pre-surgical preparation and subsequent surgical treatment options. The main part of the paper is focused on the role of morphological imaging methods (primarily computed tomography and magnetic resonance imaging) and functional imaging (scintigraphy and positron emission tomography) in the diagnosis and staging of pheochromocytomas.

Perioperative hemodynamic instability in patients undergoing laparoscopic adrenalectomy for pheochromocytoma

Perioperative hemodynamic instability still remains the biggest surgical and anesthetic challenge in surgery for pheochromocytoma. The aim of this review was to discuss pre-, intra- and postoperative factors that may impact on hemodynamic condition of a patient. It describes patients' preparation with appropriate medication, principles of surgical technique as well as risk factors for development of hemodynamic instability in postoperative period. Currently the gold standard in the treatment of pheochromocytoma is preoperative use of alpha-blockers and laparoscopic surgery. This approach allowed improving outcomes by lowering both mortality and morbidity.