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

SDH-related head and neck paragangliomas: Unraveling PET radiomics beyond 18F-FDG

Radiomics revolutionizes medical imaging by providing quantitative analysis that complements traditional qualitative assessments through advanced computational techniques. In this narrative review we have investigated the impact of succinate dehydrogenase (SDH) pathogenic variants on the radiomic profile of 18F-FDG, 18F-DOPA, and 68Ga-DOTA-peptides PET in paragangliomas, focusing on head and neck localizations (HNPGLs). This influence manifests in uptake intensity and textural heterogeneity, revealing a complex radiomic landscape that may reflect specific tumor behaviors and mutation statuses. By combining radiomic analysis with genetic data, we will gain new insights into the relationship between PET imaging features and underlying molecular changes. In the future, we envision an approach integrating macroscopic indices, such as lesion location, size, and SUV, with advanced computer-based algorithms. This comprehensive analysis could facilitate in vivo predictions of SDH pathogenic variants, thereby encouraging genetic testing, and ultimately improving patient outcomes.

[Corticotropin-producing pheochromocytoma in multiple endocrine neoplasia type 1]

A clinical case of a man 66 y.o. who was diagnosed with hormone-inactive pituitary macroadenoma complicated by corneal erosion and partial atrophy of the optic nerve of the left eye due to exophthalmos. The increase in prolactin level was regarded due to a «stalk-effect». The patient underwent a transnasal pituitary adenomectomy with subsequent regression of symptoms. After 4 years, against the background of a new coronavirus infection, increasing general weakness, headaches, a crisis increase in blood pressure and tachycardia attacks appeared. Computed tomography (CT) accidentally revealed an adrenal incidentaloma, in laboratory tests - hypercortisolism, elevated ACTH levels, hypokalemia, hyperglycemia, increased levels of metanephrine and normetanephrine. The patient developed acute steroid psychosis, after which an adrenalectomy with a tumor was performed, a pheochromocytoma was histologically confirmed. After surgery, there was a regression of symptoms, the development of adrenal insufficiency with reduced levels of ACTH and cortisol. Upon further examination, a polynodose euthyroid goiter was established, the biopsy of the nodes - Hashimoto's thyroiditis (Bethesda II). Meanwhile, primary hyperparathyroidism was detected. According to ultrasound, scintigraphy with Ts99m-Technetril and CT revealed an increase of left parathyroid gland. A bilateral revision of the neck, removal of the right upper and left upper parathyroid adenomas were performed. In the postoperative period, the levels of calcium and parathyroid hormone were normalized. Given the presence of a combination of multiple tumors of the endocrine system (primary hyperparathyroidism, corticotropin-producing pheochromocytoma, hormone-inactive pituitary macroadenoma, polynodose euthyroid goiter), the MEN1 syndrome was clinically established. The study of 2 and 10 exons of the MEN1 gene revealed no mutations, which does not exclude the presence of a hereditary syndrome. The patient continues observation. In the available literature in Russian and English languages the case of ACTH pheochromocytoma as part of the MEN type 1 syndrome have not been found. Therefore, we consider the presented case to be the first one.

Image-Guided Precision Medicine in the Diagnosis and Treatment of Pheochromocytomas and Paragangliomas

In this comprehensive review, we aimed to discuss the current state-of-the-art medical imaging for pheochromocytomas and paragangliomas (PPGLs) diagnosis and treatment. Despite major medical improvements, PPGLs, as with other neuroendocrine tumors (NETs), leave clinicians facing several challenges; their inherent particularities and their diagnosis and treatment pose several challenges for clinicians due to their inherent complexity, and they require management by multidisciplinary teams. The conventional concepts of medical imaging are currently undergoing a paradigm shift, thanks to developments in radiomic and metabolic imaging. However, despite active research, clinical relevance of these new parameters remains unclear, and further multicentric studies are needed in order to validate and increase widespread use and integration in clinical routine. Use of AI in PPGLs may detect changes in tumor phenotype that precede classical medical imaging biomarkers, such as shape, texture, and size. Since PPGLs are rare, slow-growing, and heterogeneous, multicentric collaboration will be necessary to have enough data in order to develop new PPGL biomarkers. In this nonsystematic review, our aim is to present an exhaustive pedagogical tool based on real-world cases, dedicated to physicians dealing with PPGLs, augmented by perspectives of artificial intelligence and big data.

Cystic lesions of the adrenal gland

Cystic lesions of the adrenal glands are relatively uncommon and most of them are clinically silent. Though rarely associated with malignant changes, they may carry clinically detrimental consequences if misdiagnosed. Cystic adrenal lesions exhibit a broad histomorphological spectrum, ranging from pseudocysts, endothelial cysts, epithelial cysts and parasitic cysts. Here we present the case of a young woman with left-sided abdominal pain and contrast-enhanced CT showing a 10.4×7.7×7.8 cm fluid-filled left suprarenal lesion. The patient underwent exploratory laparotomy with cyst excision, and the histopathological examination of the specimen revealed a pseudocyst of the left adrenal gland. Despite being rare, usually benign and asymptomatic, the diagnosis and management of these cystic lesions of the adrenal glands are often unclear. Any functional lesion, potentially malignant lesion or lesion more than 5 cm deserves surgical management, whereas others can be managed conservatively.

Spontaneous Retroperitoneal Bleeding as a Complication of Unusual Renal Paraganglioma

Spontaneous retroperitoneal bleeding is a rare occurrence that might have catastrophic implications. We present a 58-year-old male with a 4-day history of progressively worsening left-sided flank pain due to retroperitoneal hemorrhage from a nonfunctional renal paraganglioma. Abdominal contrast CT scan was helpful in locating the tumor, estimating tumor size and extent of bleeding, visualizing the interaction between the tumor and the surroundings, and ruling out any potential metastasis; however, it lacked specificity in identifying the origin of the mass, needing histologic investigation for a conclusive diagnosis. MRI was not available at our center. We report a rare case of spontaneous retroperitoneal bleeding as a complication of an unusual nonfunctional renal paraganglioma, which was initially misdiagnosed as renal cell carcinoma but later confirmed by postoperative histopathology.

Hereditary and Sporadic Pheochromocytoma: Comparison of Imaging, Clinical, and Laboratory Features

BACKGROUND. A considerable fraction of pheochromocytomas initially suspected to be sporadic, whether or not symptomatic, are a result of germline mutations. OBJECTIVE. The purpose of this article is to compare imaging features between hereditary and sporadic pheochromocytomas. METHODS. This retrospective study included 71 patients (39 women, 32 men; median age, 48 years) who underwent adrenal pheochromocytoma resection from January 2002 to October 2021 after preoperative CT or MRI. Two radiologists independently reviewed examinations to assess features of the largest resected pheochromocytoma. Interreader agreement was assessed by prevalence-adjusted bias-adjusted kappa coefficients; a third radiologist resolved discrepancies for further analysis. Genetic testing was used to classify pheochromocytomas as hereditary or sporadic and to classify hereditary pheochromocytomas by germline mutation clusters. Symptoms associated with pheochromocytomas and preoperative biochemical laboratory values were recorded. Groups were compared using Kruskal-Wallis, Fisher exact, and chi-square tests, and false-discovery rate-adjusted p values were computed to account for multiple comparisons. RESULTS. Hereditary pheochromocytoma (n = 32), compared with sporadic pheochromocytoma (n = 39), was associated with younger median age (38 vs 52 years, p = .001) and smaller median size (24 vs 40 mm, p < .001). Interreader agreement for CT and MRI features, expressed as kappa, ranged from 0.44 to 1.00. Hereditary and sporadic pheochromocytoma showed no difference in frequency of calcifications, hemorrhage, cystic change/necrosis, or macroscopic fat on CT, or in frequency of hemorrhage, cystic change/necrosis, macroscopic fat, or microscopic fat on MRI (p > .05). When combining CT and MRI, cystic change/necrosis was observed in 35% of hereditary versus 67% of sporadic pheochromocytomas (p = .10). Hereditary pheochromocytoma, compared with sporadic, had lower frequency of symptoms (31% vs 74%; p = .004) and lower 24-hour urinary normetanephrines (1.1 vs 5.1 times upper limits of normal, p = .006). Among hereditary pheochromocytomas, cystic change/necrosis (when assessable on imaging) was present in 18% and 45% of those with cluster 1 (n = 11) and cluster 2 (n = 21) germ-line mutations, respectively. CONCLUSION. Hereditary pheochromocytomas, compared with sporadic, are detected at a younger age and smaller size, produce lower 24-hour urinary normetanephrines, are less often symptomatic, and may less frequently show cystic change/necrosis. CLINICAL IMPACT. Imaging findings may complement clinical and biochemical features in raising suspicion for a previously unsuspected germline mutation in patients with pheochromocytoma.

Biochemically normal adrenal pheochromocytoma following extensive central necrosis in a child with von Hippel-Lindau (VHL) gene mutation

Pheochromocytomas are rare in children. The diagnosis is usually established from a raised urinary or plasma catecholamine or their metabolites. We present a girl aged 11 years who manifested with a hypertensive crisis secondary to an adrenal tumour but with unexpectedly normal urinary metanephrine and catecholamine results. She improved spontaneously following the crisis and underwent surgery later. The histopathological study confirmed a pheochromocytoma with large central necrosis. Her genetic screening reported a pathogenic von Hippel-Lindau gene mutation. Surveillance scan postsurgery detected no other tumours. Following the catecholamine crisis, an acute infarct occurred, resulting in extensive tumour necrosis and subsequent rapid remission of symptoms and paradoxically normal biochemical markers. Although not unheard of in adults, we believe this is the first reported case of an extensive spontaneous necrosis resulting in a biochemically normal pheochromocytoma in a child.

Spiral Computed Tomography in the Quantitative Measurement of the Adjacent Structure of the Left Atrial Appendage in Patients with Atrial Fibrillation

Cardiac arrhythmias are common clinical cardiovascular diseases. Arrhythmias are abnormalities in the frequency, rhythm, site of origin, conduction velocity, or sequence of excitation of the cardiac impulses. Arrhythmia mechanisms include foldback, altered autonomic rhythm, and triggering mechanisms. It can cause palpitations, dizziness, black dawn, syncope, and angina pectoris and can worsen a preexisting cardiac disease, reduce the quality of life, and increase mortality. Also, by making it one of the constant challenges for the clinical cardiovascular physician, we can get more information. The study included 94 patients with atrial fibers, including 56 men and 38 women aged 57, 46, 11, and 68 years. There are 80 patients with nonatrial fibers, including 44 men and 36 women aged 56, 10, and 83 years. Those who can perform a normal coronary angiography and exclude congenital heart disease, heart valve disease, and other cardiovascular diseases. In both groups, a 256-layer spiral CT examination was performed. A pulmonary vein scanning protocol was applied to the patients with atrial fibrillation, and this can perform normal coronary angiography and exclude those with cardiovascular diseases such as congenital heart disease and valvular heart disease. The purpose of this study is to investigate the anatomical changes of the left atrium and its adjacent structures by applying the 256 nm spiral CT imaging to visualize the left atrium and its adjacent structures and by applying the MPR technology, VR technology, and simulation endoscope techniques.

Metastatic Pheochromocytomas and Abdominal Paragangliomas

CONTEXT

Pheochromocytomas and paragangliomas (PPGLs) are believed to harbor malignant potential; about 10% to 15% of pheochromocytomas and up to 50% of abdominal paragangliomas will exhibit metastatic behavior.

EVIDENCE ACQUISITION

Extensive searches in the PubMed database with various combinations of the key words pheochromocytoma, paraganglioma, metastatic, malignant, diagnosis, pathology, genetic, and treatment were the basis for the present review.

DATA SYNTHESIS

To pinpoint metastatic potential in PPGLs is difficult, but nevertheless crucial for the individual patient to receive tailor-made follow-up and adjuvant treatment following primary surgery. A combination of histological workup and molecular predictive markers can possibly aid the clinicians in this aspect. Most patients with PPGLs have localized disease and may be cured by surgery. Plasma metanephrines are the main biochemical tests. Genetic testing is important, both for counseling and prognostic estimation. Apart from computed tomography and magnetic resonance imaging, molecular imaging using 68Ga-DOTATOC/DOTATATE should be performed. 123I-MIBG scintigraphy may be performed to determine whether 131I-MIBG therapy is a possible option. As first-line treatment in patients with metastatic disease, 177Lu-DOTATATE or 131I-MIBG is recommended, depending on which shows best expression. In patients with very low proliferative activity, watch-and-wait or primary treatment with long-acting somatostatin analogues may be considered. As second-line treatment, or first-line in patients with high proliferative rate, chemotherapy with temozolomide or cyclophosphamide + vincristine + dacarbazine is the therapy of choice. Other therapies, including sunitinib, cabozantinib, everolimus, and PD-1/PDL-1 inhibitors, have shown modest effect.

CONCLUSIONS

Metastatic PPGLs need individualized management and should always be discussed in specialized and interdisciplinary tumor boards. Further studies and newer treatment modalities are urgently needed.

Adrenal metastases: early biphasic contrast-enhanced CT findings with emphasis on differentiation from lipid-poor adrenal adenomas

AIM

To evaluate the accuracy of unenhanced attenuation and early biphasic contrast-enhanced computed tomography (CT) in differentiating adrenal metastases (AMs) from lipid-poor adrenal adenomas (AAs).

MATERIALS AND METHODS

This retrospective study included 37 patients with 50 AMs and 86 patients with 89 lipid-poor AAs. Quantitative data including the longest diameter (LD), the shortest diameter (SD), LD/SD ratio, CT attenuation values (CTu, CTa, CTv), degree of enhancement (DEAP, DEPP, DEpeak, APW, RPW), and peak enhanced/unenhanced (PE/U) CT attenuation ratio were obtained. Qualitative data including enhancement pattern, location, shape, the presence of calcification or haemorrhage, and intra-lesion necrosis were analysed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were also calculated.

RESULTS

The PE/U ratio (≤1.25), CTu (≥32.2 HU), DEpeak (≤43.15 HU), DEPP (≤37.65 HU), presence of intralesional necrosis, location (bilateral adrenal glands), and irregular shape were significant variables for differentiating AMs from lipid-poor AAs (p<0.05). Among them, PE/U ratio (≤1.25) was of greater value in differentiating the two adrenal diseases, with sensitivity, specificity, area under the receiver operating curve (ROC) curve (AUC) of 92%, 84%, 0.933, respectively. When at least any three of above criteria were combined, the sensitivity, specificity, PPV, and NPV for diagnosing AMs were 88%, 93%, 88%, and 88%, respectively.

CONCLUSIONS

These seven CT criteria are conducive to differentiate AMs from lipid-poor AAs. Early biphasic contrast-enhanced CT is a high-efficient and practical imaging tool in differentiating them.

A Nomogram for Predicting Intraoperative Hemodynamic Instability in Patients With Pheochromocytoma

PURPOSE

Surgical removal of pheochromocytoma (PCC), including open, laparoscopic, and robot-assisted adrenalectomy, is the cornerstone of therapy, which is associated with high risk of intraoperative and postoperative life-threatening complications due to intraoperative hemodynamic instability (IHD). This study aims to develop and validate a nomogram based on clinical characteristics as well as computed tomography (CT) features for the prediction of IHD in pheochromocytoma surgery.

METHODS

The data from 112 patients with pheochromocytoma were collected at a single center between January 1, 2010, and December 31, 2019. Clinical and radiological features were selected with the least absolute shrinkage and selection operator regression analysis to predict IHD then constitute a nomogram. The performance of the nomogram was assessed in terms of discrimination, calibration, and clinical utility.

RESULTS

Age, tumor shape, Mayo Adhesive Probability score, laterality, necrosis, body mass index, and surgical technique were identified as risk predictors of the presence of IHD. The nomogram was then developed using these seven variables. The model showed good discrimination with a C-index of 0.773 (95% CI, 0.683-0.862) and an area under the receiver operating characteristic curve (AUC) of 0.739 (95% CI, 0.642-0.837). The calibration plot suggested good agreement between predicted and actual probabilities. Besides, calibration was tested with the Hosmer-Lemeshow test (P = 0.961). The decision curve showed the clinical effectiveness of the nomogram.

CONCLUSIONS

Our nomogram based on clinical and CT parameters could facilitate the treatment strategy according to assessment of the risk of IHD in patients with pheochromocytoma.

Diagnostic Value of Unenhanced CT Attenuation and CT Histogram Analysis in Differential Diagnosis of Adrenal Tumors

Background and Objectives: Our aim was to verify the optimal cut-off value for unenhanced CT attenuation and the percentage of negative voxels in the volume CT histogram analysis of adrenal masses. Materials and Methods: We retrospectively analyzed the CT data of patients who underwent an adrenalectomy in the period 2002-2019. In total, 413 adrenalectomies were performed. Out of these, 233 histologically verified masses (123 adenomas, 58 pheochromocytomas, 18 carcinomas, and 34 metastases) fulfilled the inclusion criteria and were selected for analysis. The mean unenhanced attenuation in Hounsfield units (HU) and the percentage of voxels with attenuation less than 0 HU (negative voxels) were measured in each mass. Results: The mean unenhanced attenuation with a cut-off value of 10 HU reached a sensitivity of 59.4% and a specificity of 99.1% for benign adenomas. The mean unenhanced attenuation with a cut-off value of 15 HU reached a sensitivity of 69.1% and a specificity of 98.2%. For the histogram analysis, a cut-off value of 10% of negative pixels reached a sensitivity of 82.9% and a specificity of 98.2%, whereas a cut-off value of 5% of negative pixels reached a sensitivity of 87.8% and a specificity of 75.5%. The percentage of negative voxels reached a slightly better area under the curve (0.919) than unenhanced attenuation (0.908). Conclusion: Mean unenhanced attenuation with a cut-off value of 10 HU represents a simple tool, and the most specific one, to distinguish adrenal adenomas from non-adenomas. CT histogram analysis with cut-off values of 10% of negative voxels improves sensitivity without any loss of specificity.

Genetics, diagnosis, management and future directions of research of phaeochromocytoma and paraganglioma: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

: Phaeochromocytoma and paraganglioma (PPGL) are chromaffin cell tumours that require timely diagnosis because of their potentially serious cardiovascular and sometimes life- threatening sequelae. Tremendous progress in biochemical testing, imaging, genetics and pathophysiological understanding of the tumours has far-reaching implications for physicians dealing with hypertension and more importantly affected patients. Because hypertension is a classical clinical clue for PPGL, physicians involved in hypertension care are those who are often the first to consider this diagnosis. However, there have been profound changes in how PPGLs are discovered; this is often now based on incidental findings of adrenal or other masses during imaging and increasingly during surveillance based on rapidly emerging new hereditary causes of PPGL. We therefore address the relevant genetic causes of PPGLs and outline how genetic testing can be incorporated within clinical care. In addition to conventional imaging (computed tomography, MRI), new functional imaging approaches are evaluated. The novel knowledge of genotype-phenotype relationships, linking distinct genetic causes of disease to clinical behaviour and biochemical phenotype, provides the rationale for patient-tailored strategies for diagnosis, follow-up and surveillance. Most appropriate preoperative evaluation and preparation of patients are reviewed, as is minimally invasive surgery. Finally, we discuss risk factors for developing metastatic disease and how they may facilitate personalised follow-up. Experts from the European Society of Hypertension have prepared this position document that summarizes the current knowledge in epidemiology, genetics, diagnosis, treatment and surveillance of PPGL.