Incidental Serous Tubal Intraepithelial Carcinoma Finding in a Nepalese Patient Undergoing Opportunistic Salpingectomy and the Discovery of a BRCA1 Pathogenic Variant

Abstract

BACKGROUND: Serous tubal intraepithelial carcinoma lesions are the precursor to high-grade serous ovarian carcinomas, which have the highest mortality rate among gynecologic malignancies. In women diagnosed with high-grade serous ovarian carcinoma, 20% of the carcinomas are found to be secondary to hereditary causes, with the majority being associated with germline pathogenic variants in BRCA1 and BRCA2 genes. Patients with a pathogenic variant are at high risk for developing high-grade serous ovarian carcinoma, so it is recommended that they undergo risk-reducing salpingo-oophorectomy in their 30s–40s. Opportunistic salpingectomy is the only ovarian cancer prevention method available for patients at average risk. Although serous tubal intraepithelial carcinoma lesions are rare in women at average risk, studies quote incidental serous tubal intraepithelial carcinoma lesion findings in 1–7% of patients undergoing opportunistic salpingectomy. CASE: A 38-year-old woman, gravida 2 para 2, of Nepalese ethnicity had an incidental finding of a serous tubal intraepithelial carcinoma lesion at the time of opportunistic salpingectomy for permanent sterilization at cesarean delivery. The serous tubal intraepithelial carcinoma lesion was found with representative sampling of the fallopian tubes because the patient was considered to be at average risk for ovarian cancer. This method is much less sensitive than the Sectioning and Extensively Examining the Fimbriated End (SEE-FIM) protocol, which is used with women known to be at high risk. This ultimately led to discovery of a BRCA1 mutation in the patient. CONCLUSION: The SEE-FIM protocol is used to identify serous tubal intraepithelial carcinoma lesions, but it is not routinely used on fallopian tubes of patients at average risk. Using the SEE-FIM protocol would lead to fewer missed serous tubal intraepithelial carcinoma lesions, but it is unclear how much extra cost and effort would be required to implement this protocol. There are knowledge gaps when it comes to understudied populations and hereditary breast and ovarian cancer gene prevalence. Studies show that current BRCA prediction models underestimate hereditary breast and ovarian cancer gene prevalence in Asian populations. Diagnosing serous tubal intraepithelial carcinoma lesions in understudied populations could lead to the discovery of a hereditary breast and ovarian cancer pathogenic variant that the patient may not have discovered until after a cancer diagnosis. Identification of a serous tubal intraepithelial carcinoma in a patient at average risk should lead to a referral for genetic counseling and screening.