Pathology of the Fallopian Tube: Tubal Involvement by Ovarian Tumors and Incidental Findings in the Nontumoral Setting

The fallopian tube is thought to be the site of origin of most high-grade serous carcinomas (HGSCs). However, how often the tube is abnormal in the setting of other ovarian tumors is unknown. The aim of this study is to define the frequency of tubal abnormalities in the tumoral (n = 245) and nontumoral (n = 184) setting. We found that in ovarian tumors, 52.2% of the tubes were normal, while 39.2% were affected by the tumor. Abnormal tubes were found in 80% of HGSCs, in 21% of mucinous carcinomas, in 83.3% of seromucinous carcinomas, in 33.3% of endometrioid carcinomas, in 20% of clear-cell carcinomas, and in 10.5% of borderline tumors. Among normal tubes, almost 70% were histologically normal; transitional metaplasia was present in 17.4%, endometriosis in 8.1%, and adenofibroma in 2.2%, and 1.1% had an incidental serous intraepithelial tubal carcinoma. To conclude, the fallopian tube is abnormal in most serous carcinomas, and in a smaller number of endometrioid, clear-cell and mucinous carcinomas as well as borderline tumors. It is often abnormal in seromucinous tumors, but larger series are needed to study this rare subtype.