Merkel cell carcinoma of the vulva.

The authors describe the clinical and histologic findings in a case of Merkel cell carcinoma of the vulva, which was associated with squamous cell carcinoma in situ and lichen sclerosus. Electron microscopy of the tumor revealed membrane-bound granules. At postmortem examination, metastases from this primary skin tumor were found in the pelvic lymph nodes, in paraortic lymph nodes, in the liver, and in vertebral bodies. The case is unusual because Merkel cell tumors are usually found on the face or the extremities and seldom metastasize widely.