A precursor lesion for ovarian carcinoma, tubal intraepithelial carcinoma (TIC), has been identified in BRCA-mutation carriers undergoing prophylactic bilateral salpingo-oophorectomy (pBSO). Other lesions were also identified in fallopian tubes, but different terminology, interpretation, and lack of knowledge of normal epithelium, have hampered to unravel their possible role in carcinogenesis. The aim of this study is to classify tubal epithelial lesions in BRCA-mutation carriers and controls to enable comparison of prevalence, area of localization, and possible malignant potential.

Two hundred twenty-six BRCA1/2-mutation carriers were included; ovaries and fallopian tubes, embedded completely, were reviewed. Controls included 105 women who underwent BSO for non-malignant reasons. Tubal epithelial lesions included the following categories: hyperplasia, minor epithelial atypia, TIC, and invasive carcinoma.

Tubal neoplasia was identified in 7.1% (invasive carcinoma, 0.9%; TIC, 6.2%) of BRCA-mutation carriers compared to none in controls (p=0.004, Fisher's exact test). Hyperplasia and minor epithelial atypia were identified in 41.6% BRCA-mutation carriers and compared to 58.1% in controls (p=0.005, Pearson's chi square). Invasive carcinoma and TIC showed preference for the fimbrial ends (p=0.027, Pearson's chi square), while hyperplasia and minor epithelial atypia displayed more variation in localization.

Invasive tubal carcinoma and TIC were limited to BRCA-mutation carriers, whereas hyperplasia and minor epithelial atypia were commonly found in both BRCA-mutation carriers and controls. It is suggested that hyperplasia and minor atypia represent variations of normal tubal epithelium instead of premalignant lesions. Furthermore, total salpingectomy is strongly recommended as most but not all TIC occurred in the fimbriae.