Answer: Adrenal cortical carcinoma, sarcomatoid

Histology: Much of this lesion consists of sheets of epithelioid eosinophilic cells. The cells have finely vacuolated, eosinophilic cytoplasm. These cells show areas of mitotic activity and are associated with extensive necrosis. These areas labeled with Melan A but not for HMB45, consistent with adrenal cortical carcinoma. However, in addition to this component, there’s a component of hyperchromatic cells associated with deeply eosinophilic, spindled cytoplasm. The latter cells label for desmin and show nuclear labeling for myogenin.

Therefore, this lesion represents adrenal cortical carcinoma with a sarcomatoid (rhabdomyoblastic) component (carcinosarcoma).

Discussion: The presence of the rhabdomyosarcoma component distinguishes this case from a typical adrenal cortical carcinoma. A composite pheochromocytoma contains pheochromocytes along with a component of ganglion cells, and reflects the common origin of pheochromocytes and ganglion cells from the neural crest. Ganglioneuroblastoma contains small foci of primitive neuroblasts set in the background of extensive ganglion cell differentiation.

Sarcomatoid change with adrenal cortical carcinoma is extremely rare, and it’s been a subject of case reports.