ACTH-Independent Cushing’s Syndrome Associated with Left Adrenocortical Oncocytoma of Uncertain Malignant Potential

Abstract EN

Adrenocortical oncocytomas are rare and mostly nonfunctioning neoplasms.

We report the case of a 27-year-old woman diagnosed with an ACTH-independent Cushing’s syndrome due to left adrenal oncocytoma.

She underwent laparoscopic adrenalectomy.

Histopathological examination revealed an oncocytoma of uncertain malignant potential with a low Ki-67 proliferation index, inhibin A positivity, and chromogranin A negativity.

Electron micrographs confirmed adrenal oncocytoma cells, characterized by the presence of a large amount of mitochondria.

The postoperative course was uneventful, and the patient experienced a progressive regression of Cushing-related symptoms.

Periodical follow-ups with MRI and cortisol dosage are required due to the neoplasm’s uncertain malignant potential.

Considerations on the diagnosis, pathology findings, clinical remarks, and interventions are made.