Parafallopian tube transitional cell carcinoma.

BACKGROUND Transitional cell carcinoma (TCC) has recently been acknowledged as a distinct histologic pattern of the uncommon primary fallopian tube carcinoma. However, rare cases of TCC that are closely associated to the extraluminal portion of the tube remain widely unrecognized. CASE We present a left adnexal high-grade TCC in a 56-year-old postmenopausal woman with an elevated serum CA-125 level. The tumor was attached by a small stalk to the serosal surface of the left fallopian tube and was completely separate from the uninvolved uterus and ipsilateral ovary. Histologic examination of the tubal lumen epithelium revealed neither atypia nor involvement by the neoplasm. Immunohistochemistry showed the tumor cells to be positive for pankeratin, calretinin, progesterone and estrogen receptors, and cytokeratin 7, and negative for cytokeratin 20, consistent with a Mullerian derivation. CONCLUSION Our case represents the fourth reported instance of a primary paratubal TCC. Perhaps, this entity falls under a previously unrecognized category of carcinomas that collectively may arise from Walthard's rest, paratubal cyst, or directly from the tubal serosa.