Malignant melanoma metastatic to the ovary

The clinical and pathologic features of 10 patients with malignant melanoma metastatic to the ovary were studied. Seven were from surgical patients who presented with possible primary ovarian neoplasms and three were autopsy cases. Six had unilateral involvement, and all but one of the metastases were grossly cystic. Two predominant histologic patterns were identified: the more common (six cases) consisted of small oval to spindle-shaped cells with inconspicuous or absent melanin pigment and a focal storiform architecture. Three of these six were initially misinterpreted as ovarian stromal neoplasms. The other four tumors had large epithelioid cells with abundant cytoplasm and melanin pigment, and were readily classified as metastatic melanoma. Six of the seven surgical cases were reactive with antibodies to S-100 protein and vimentin but nonreactive with antibodies to keratin.