Incidental Finding of Adrenal Oncocytoma After Right Robotic Adrenalectomy: Case Report and Literature Review

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.

A case of a borderline adrenal oncocytoma in a 62-year old female

INTRODUCTION

Adrenal oncocytomas are a rare pathology and only about 160 cases have been reported in the literature.

CASE DESCRIPTION

We describe the case of a 62-year old female with an incidentaloma found in the right adrenal gland on a CT scan. Endocrine testing showed a non-secreting lesion. An MRI was performed to get a more precise diagnosis. It excluded a simple adenoma and a malignant tumor had to be suspected. Open adrenalectomy was performed, and pathology results confirmed a borderline adrenal oncocytoma.

DISCUSSION

Oncocytomas are usually found in the kidneys, salivary glands, parathyroid, lung, pituitary gland, and ovaries. It is important to differentiate them from, for example, pheochromocytomas, adrenal cortical carcinoma, and metastasis. Most oncocytomas are non-functioning (17% are functional). Usually, they are found as incidentalomas on a CT or MRI scan. The only way to confirm the diagnosis at present is pathological examination. Bisceglia and his colleagues have proposed a new system to classify adrenal oncocytomas. The presence of one major criterion indicates malignancy, the presence of one to four minor criteria is indicative of uncertain potential. The absence of all major and minor criteria indicates benign behavior. Treatment options are open surgery, laparoscopic surgery and rarely robotic surgery.

CONCLUSION

An adrenal oncocytoma remains a rare diagnosis and has a wide array of differential diagnosis. It should be treated by surgical removal and a close follow up is suggested. More research should be done regarding diagnosis, treatment and follow-up.

Oncocytic subtypes of adrenal cortical carcinoma: Aggressive in appearance yet more indolent in behavior?

BACKGROUND

Adrenal cortical carcinoma is an aggressive malignancy and typically heralds a poor prognosis. The oncocytic subtype of this neoplasm is rare but may be associated with more favorable outcomes.

METHODS

The Provincial Cancer Registry was searched for cases of adrenal cortical carcinoma between 1992 and 2017. Comprehensive chart reviews were performed and data gathered related to presentation, treatment, and outcomes.

RESULTS

In the study, 82 patients with adrenal cortical carcinoma were identified. Complete data were available for 67 patients (82%). In the 41 patients who underwent resection, 9 (22%) had oncocytic subtypes. When compared with the total group of adrenal cortical carcinomas, the oncocytic subtypes were larger at presentation (19.8 cm vs 11.0 cm), more commonly symptomatic and hormonally active, and despite larger tumor size, were often early stage I and II. Recurrent disease was observed in 3 out of 9 oncocytic subtype (vs 23 out of 32 adrenal cortical carcinoma), with greater median time to recurrence (17.5 vs 8 months). Univariate analysis suggested that age, T-stage, M-stage, and overall stage were associated with survival. There was a trend toward improved overall survival for patients with oncocytic subtype on Kaplan-Meier and multivariate analysis.

CONCLUSION

Despite our small numbers of patients with oncocytic subtype, our data suggest that oncocytic subtype are typically larger at presentation but more often early stage and recur less frequently than adrenocortical carcinomas. Modifications to treatment and surveillance strategies may be appropriate in this subtype.