Multiple neuroectodermal tumors arising in a mature cystic teratoma of the ovary.

Benign cystic teratomas are common, comprising 11-20% of all ovarian tumors. Neural elements can be identified in 38% of teratomas, but the development of a malignant neural neoplasm in an ovarian tumor of this type is rare. Multiple neuroectodermal tumor foci have not been previously described in association with a mature cystic teratoma of the ovary.