MERKEL CELL-CARCINOMA OF THE VULVA

Merkel cell carcinoma is a very rare tumor. This is why it is not know n whether this neoplasm behaves differently in the vulvar location tha n at other sites. We present a patient with a Merkel cell carcinoma as sessed with a light optical microscope, immunohistochemistry, and elec tron microscope. Only eight previous cases have been reported in the l iterature. We discuss pathologic findings, such as histologic trabecul ar pattern under the optical microscope and neurosecretory granules (s imilar to Merkel cell carcinoma of the skin) under the electron micros cope, Also discussed are the results of immunohistochemistry for low-m olecular-weight cytokeratin, neuron-specific enolase, chromogranin, an d Leu 7, and molecular study of N-ras, K-ras, N-myc, and p53 genes. Li ttle is known about Merkel cell carcinoma of the vulva, but it seems t o have a more aggressive behavior and poorer prognosis than Merkel cel l carcinoma at other sites. (C) 1997 Academic Press.