Non-functional adrenocortical adenoma: a unique case of combination with myelolipoma and endothelial cysts.

A case of non-functioning adrenocortical adenoma combined with myelolipoma and endothelial cysts is reported. A 72-year-old Japanese female was noticed to have right renal and left adrenal tumors by an abdominal CT scan. At surgery, the mildly enlarged left adrenal gland contained a well-demarcated tumor. Macroscopically, it was yellowish to dark red or grayish in color, and was characterized by geographic appearance on the cut surface. Histopathological examination revealed a solid proliferation of clear or compact cells and a normal rim of adrenal gland, coexisting with vascular multiple cysts and myelolipomas. The cysts were filled with clotted blood, fibrinous material, or thrombi, and were partially lined with flattened endothelial cells with focal papillary hyperplasia, which were immunohistochemically positive for CD31 and CD34. These cystic walls were often thickened with hyalinized fibrosis and calcification, and were connected to myelolipomatous elements. To our knowledge, this is the first case report of adrenocortical adenoma associated with myelolipoma and endothelial cysts. It is probable that the extensive degeneration in adenoma might induce myelolipomatous metaplasia and cystic vascular formation.