High-grade serous carcinoma of fallopian tube with yolk sac tumor differentiation in a postmenopausal patient.

Yolk sac tumors (YSTs) are the second most common germ cell malignancy of the ovaries, generally presenting in children and young women. However, they rarely occur in the fallopian tubes of postmenopausal patients. The current rare case is composed of yolk sac tumor differentiation within high-grade serous carcinoma (HGSC) arising in the fallopian tube of a 68-year-old woman. Serum α-fetoprotein was much higher than normal level. This case exhibited some areas of glandular architecture with positivity for SALL4, AFP, and Glypican-3 and negative staining for PAX8, supporting a germ cell tumor differentiation. By reviewing the published literature, we believe that YSTs, whether or not associated with an epithelial component detected histologically in older patients, constitute a single entity that is different from YSTs in younger patients. Above all, the pathologist must check carefully tissue stained with hematoxylin-eosin especially in postmenopausal women with ovarian, fallopian tube, or endometrial mass and an elevated serum α-fetoprotein level. Neoplasms of this type should be treated aggressively, and should respond to platinum-based chemothotherapy.