Primary malignant melanoma arising in an ovarian dermoid cyst: proposed use of radioimmunoscintigraphy with 99mTc-F(ab')2 antimelanoma antibody for staging and follow-up. Case report.

A case of primary amelanotic ovarian malignant melanoma arising in a dermoid cyst is presented. Grossly, inside the cyst, pigmented solid lesions were not detected. Histologically, an area with undeniable malignant microscopic features was revealed and its melanomatous identity was confirmed by positive S-100 protein and melanoma antigen immunoreactivity. Recently, after 21 months from surgery this patient has also undergone radioimmunoscintigraphy (RIS) with 99mTc labelled antimelanomatous antibodies which revealed a possible secondary paracolic localization. Regardless of this evidence, although the patient has always refused chemotherapy and second look surgery for removal of the suspicious area, she is alive 1 year after surgery and now doing well. The authors also report the usefulness of employing the RIS technique in evaluating the metastatic spread in this type of malignancy.