Neuroendocrine (Merkel cell) carcinoma of the vulva: a case report and review of the literature.

The clinical and pathologic features of a vulvar neuroendocrine (Merkel cell) neoplasm are presented. Cytologic studies of material obtained from needle aspiration suggested that the tumor was a small cell neoplasm possibly of neuroendocrine derivation. The light-microscopic findings of sheets of small, uniform cells were consistent with a diagnosis of neuroendocrine tumor. The electron-microscopic characteristics, including the presence of neurosecretory granules, confirmed the diagnosis of a neuroendocrine (Merkel cell) carcinoma. Regional lymph node metastases were present at the time of initial surgery, and both local and distant metastases developed 8 months later. A comprehensive pretreatment metastatic evaluation is recommended. The role of chemotherapy for primary therapy is considered.