Low-Grade Serous Tubal Intraepithelial Neoplasia (Serous tubal intraepithelial lesion)

Low-grade serous tubal intraepithelial neoplasia (STIN) is synonymous with a proliferation produced when there are both a mutation and an inactivation of p53 and is similar to STIC.

Like STICs, STINs are uncommon, found in less than 1 : 500 routine salpingectomies. It is found in less than 10% of tubes removed during risk reduction salpingo-oophorectomy (RRSO) for inherited BRCA1 or BRCA2 mutations, the percentages fluctuating as a function of patient age. It is discovered more commonly (just how commonly we do not know) in fallopian tubes of women with high-grade pelvic serous carcinoma. It can be associated with, and presumably preceded by, a benign nonatypical clonal expansion of secretory cells with p53 mutations (p53 signatures).

Low-grade STINs are discovered on histologic exam of the tubes, either in RRSOs or tubes removed during surgery for advanced serous carcinoma. The former are usually asymptomatic, and the latter present with the usual signs and symptoms of advanced disease. Low-grade STINs are uncommon in the asymptomatic woman without an inherited BRCA1 or BRCA2 mutation.