A rare case of oncocytic adrenocortical carcinoma clinically presented as an incidentaloma

Oncocytic adrenocortical neoplasm with undetermined malignant potential and autonomous cortisol secretion

Increasing incidence of adrenal incidentalomas with hypercortisolemia not associated with overt features of Cushing's syndrome has led to the evolution of the term autonomous cortisol secretion. Oncocytic adrenocortical neoplasms (OANs) are rare adrenal cortex neoplasms with only 250 reported cases worldwide. We present a woman in her 30s with menometrorrhagia, weight gain and increasing abdominal girth who was found to have a large right adrenal mass on abdominal CT scan. Serum cortisol was not suppressed after 1 mg dexamethasone (31.5 µg/dL) and adrenocorticotrophic hormone was not detectable (<1.0 pg/mL). She underwent right adrenalectomy under glucocorticoid coverage. Hypertension, weight, visceral adiposity and menometrorrhagia improved postoperatively. Histopathology with immunohistochemistry showed OAN with undetermined malignant potential. These kinds of tumours can only be definitively diagnosed postsurgically using the Lin-Weiss-Bisceglia system. Although they have better prognosis compared with adrenocortical carcinomas and do not require chemotherapy, patients should be closely monitored to identify recurrence promptly.

Oncocytic Adrenocortical Carcinoma With Low 18F-FDG Uptake and the Absence of Glucose Transporter 1 Expression

Adrenocortical carcinoma (ACC) is a rare tumor, and some histological variants (oncocytic, myxoid, and sarcomatoid ACCs) have been reported in addition to the conventional ACC. Among these subtypes, oncocytic ACC is histologically characterized by the presence of abundant eosinophilic granular cytoplasm in the carcinoma cells owing to the accumulation of mitochondria, which generally yields high ¹⁸F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET). Herein, we report the case of a 21-year-old woman with oncocytic ACC with low FDG uptake on PET scan. Her circulating levels of androgens were high, and androgen-synthesis enzymes were detected in carcinoma cells. The patient also had hypocholesterolemia. However, glucose transporter 1 (GLUT1) was not detected in the tumor, which was considered to account for the low FDG uptake by the tumor. To the best of our knowledge, this is the first case of low FDG uptake by oncocytic ACC without GLUT1 expression. Additionally, since hypocholesterolemia was reported in 3 previous reports of androgen-producing tumors, a possible correlation between androgenicity in adrenal tumors and the development of hypocholesterolemia could be postulated; however, further investigations are needed for clarification. This case highlights important information regarding the diversity of ACC and its impact on hypocholesterolemia.

Adrenocortical Carcinoma: Updates of Clinical and Pathological Features after Renewed World Health Organisation Classification and Pathology Staging

Adrenocortical carcinoma (ACC) is a heterogenous group of diseases with different clinical behaviour between adult and paediatric patients. In addition, three histological variants, oncocytic, myxoid and sarcomatoid are noted on the recent World Health Organisation (WHO) classification of ACC. A review of recent literature showed that the different types of ACC have distinctive demographic data, clinical presentation, pathology, biological behaviour, genomic and patients' prognosis. In addition, recent updates of pathology staging for ACC allow refinement of prognostic grouping for planning treatment of the patients with ACC. These advances in genomic, pathology and staging have driven the development of standardisation of pathology reporting. International standardisation of pathological reporting of adrenocortical carcinoma and adaption to local pathology communities provide universal platforms for clinicians and researchers involved in the management of patients with ACC. To conclude, all these advances in the field of pathology will improve development of management strategies including improvement of clinical care, development of prognostic markers and testing of novel therapeutic approaches for patients with adrenocortical carcinoma.