Malignant melanoma arising in mature ovarian cystic teratoma (dermoid cyst). Report of two cases and literature analysis.

Malignant melanoma may originate from melanocytes in ovarian cystic teratomas (dermoid cysts). Two cases are reported here and an additional 17 cases are found in a literature review covering 1903-1995. The review also found cases of benign and malignant melanotic ovarian lesion unassociated with dermoid cyst, including four melanomas, three cases of benign nevus, five cases of benign melanosis, and four cases of benign and malignant retinal anlage tumors. The extremely rare primary ovarian melanoma may be differentiated from the more common melanoma metastatic to the ovaries by its unilaterality, the presence of junctional change, and a detailed history and physical examination to exclude another primary site. Overall, 50% of patients with Stage I dermoid-associated melanoma were alive at 2 years compared with 89% of patients with Stage I dermoid-associated squamous carcinoma at 5 years. In the last 10 years, however, with the application o aggressive chemotherapy, survival has improved.