Adrenal incidentalomas are commonly detected and their assessment is a clinical scenario frequently encountered by endocrinologists. Investigation to exclude autonomous hormonal secretory function and malignant potential is essential, and often guides management. Characterising adrenal masses using contrast-enhanced CT utilises understanding of typical perfusion pattern of benign adenomas. Features indicating malignant risk include large size, calcifications, irregular margins and necrosis.1
The case presented is a 43-year-old female with an incidentally detected right adrenal mass. Background includes obesity (BMI 39kg/m2), bicuspid aortic valve and recently diagnosed hypertension, controlled on amlodipine and perindopril. Family history includes maternal Ehlers-Danlos syndrome and is negative for malignancy. Investigations revealed no excess secretion of cortisol, aldosterone, androgens or catecholamines, normal renal function and normokalaemia. Imaging demonstrated a 50mm heterogenous mass, with punctate focus of calcification, and washout characteristics not typical of a lipid-rich adenoma. There was no evidence of metastatic disease on 18F-FDG PET, but the lesion was FDG-avid. Imaging features raised concern for adrenocortical carcinoma. Adrenalectomy was performed laparoscopically, with successful en-bloc resection and no evidence of invasion into surrounding structures. Recovery was uncomplicated. Histopathology revealed a benign adrenal ganglioneuroma.
Adrenal ganglioneuromas are benign differentiated neoplasms which arise from neural crest cells and mostly contain Schwann cells, ganglion cells and fibrous tissue. In workup, they are usually non-functional and detected as a bulky incidentaloma.2 They are rare, with an estimated incidence of one per million people, and only accounting for 0.2%-2% of all adrenal tumours.3 They are most often sporadic although can rarely be associated with genetic syndromes (i.e., MEN2 or neurofibromatosis type 1). The diagnosis is rarely suggested pre-operatively given the lack of pathognomonic imaging findings. Ganglioneuromas are frequently atypical with heterogeneity, contrast washout of <50%, and calcifications.4 Diagnosis relies on histopathological features. Current evidence supports an excellent prognosis, with a low post-operative recurrence rate.5