[Adenocarcinomas with mesonephric features in gynecologic tract: a clinicopathological analysis of seven cases]

Objective: To investigate and compare the histologic characteristics of adenocarcinomas with mesonephric features located in different parts of the gynecologic tract. Methods: Two cases of mesonephric adenocarcinomas (MA) of the cervix and 5 cases of mesonephric-like adenocarcinomas (MLA) of the uterus and ovary were collected in Women's Hospital, School of Medicine, Zhejiang University from January 2018 to October 2020. Hematoxylin-eosin staining, immunohistochemistry and KRAS mutation testing were performed together with review of literature. Results: MA of the cervix as well as MLA of the uterus and ovary had similar morphologic features, showing an admixture of glandular, tubular, papillary and solid growth patterns. However, both MA cases were located in cervical stroma, which demonstrated residual mesonephric ducts present at the periphery. All four uterine MLA cases extensively involved the endometrium and myometrium. The ovarian MLA case was associated with endometriosis. No residual mesonephric ducts were present in the MLA cases. Immunohistochemically, GATA3 was positive in all seven MA/MLA cases. TTF1 was expressed only in 4/5 MLA cases. ER and PR were negative and p53 was wild-type in all cases. KRAS mutation was detected in all five cases. During the 6-32 months of follow-up, one patient developed recurrence and the others were tumor-free. Conclusions: In the gynecologic tract, both MA in cervix and MLA in uterus and ovary have similar morphologic features, immunohistochemical expression and KRAS mutation. However, distinct from MA that originates from mesonephric remnant, MLA is closely related to Mullerian epithelium.