Prostate-Type Adenocarcinoma in Mature Cystic Ovarian Teratoma.

We report our experience with prostatic-type tissue in ovarian teratomas, and in particular we highlight a case of prostatic-type adenocarcinoma arising within a mature cystic ovarian teratoma in a 32-yr-old woman. On gross examination, the cyst consisted of typical features of a dermoid cyst. Closer examination revealed a single 1.5-cm solid nodule within the cyst. Microscopically, it was composed of a small cyst-like structure lined by urothelium and to one side glandular and stromal tissue consistent with prostate parenchyma. Within the prostatic-type tissue, there were malignant glands morphologically and immunohistochemically supportive of prostatic-type adenocarcinoma Gleason score 3+3=6. There were also areas consistent with high-grade prostatic intraepithelial neoplasia. Although there are several reports in the literature of benign prostatic-type tissue arising within ovarian as well as testicular teratomas, to our knowledge, prostatic-type adenocarcinoma arising in a mature ovarian teratoma is an extremely rare phenomenon, with only 1 previous report in the literature.