An ovarian mucinous adenocarcinoma arising from mature cystic teratoma associated with respiratory type tissue: a case report.

Mature cystic teratoma (dermoid cyst) is the most common benign germ cell tumor of the ovary, accounting for approximately 30% of all ovarian tumors. Malignant transformation is rare; the most frequent transformation reported is to squamous-cell carcinoma in 80% of cases, whereas transformation to adenocarcinoma is described in about 7% of cases. We report a case of malignant transformation to mucinous adenocarcinoma arising from respiratory-like epithelium in a mature teratoma of the ovary.