Myelolipomatous Foci in an Adrenal Adenoma Causing Cushing's Syndrome?

We present a case of Cushing's syndrome in a 60-year old man. Abdominal imaging revealed a right adrenal mass. After confirmation of the diagnosis, the right adrenal gland was resected and revealed a tumor containing a combined myelolipoma and adenoma of the adrenal gland. After surgical removal of the adrenal mass, the symptoms and clinical signs of Cushing's syndrome resolved gradually. Immunohistochemical analysis of the adrenal adenoma specimens showed a high lymphocyte population, particularly within the myelolipoma, and an unusually marked intermingling of myelolipomatous and adrenocortical tumor cells. Adrenocortical clear cells were found in direct contact with T and B lymphocytes. Immune-endocrine mechanisms may have triggered the corticotropin-independent adrenal Cushing's syndrome in this patient.