Oncocytic adrenocortical neoplasm of borderline uncertain malignant potential diagnosed after robot-assisted adrenalectomy case report

Background: Adrenal incidentalomas are radiologically discovered tumors that represent a variety of pathologies, with the diagnosis clinched only on surgical pathology. These tumors may be clinically monitored, but triggers for surgery include size > 4 cm, concerning features on radiology, or hormonally functioning. Adrenal oncocytic neoplasms (AONs) are notably rare and typically nonfunctional tumors that are discovered as incidentalomas and exist on a spectrum of malignant potential.

Case presentation: We discovered an exceptionally large (15 cm in the greatest dimension) incidentaloma in a 73-year-old man with left back pain and he was treated with robotic-assisted adrenalectomy. Surgical pathology was consistent with AON of borderline uncertain malignant potential; adjuvant mitotane and radiation were omitted based on shared decision-making.

Conclusion: Large AONs are rare, usually benign tumors that can be safely treated with robotic-assisted adrenalectomy. Surgical pathology is the crux of diagnosis and post-operative management, as it informs both the initiation of adjuvant therapy and the stringency of post-operative surveillance.