Serous tubal intraepithelial carcinoma in a Japanese woman with a deleterious BRCA1 mutation.

Risk-reducing salpingo-oophorectomy for reducing future cancer risk in women with hereditary breast and ovarian cancer syndrome is rarely performed in Japan; therefore, the cancer preventive effect of risk-reducing salpingo-oophorectomy for hereditary breast and ovarian cancer syndrome among the Japanese population remains unclear. Here, we report the first case of serous tubal intraepithelial carcinoma identified through a risk-reducing salpingo-oophorectomy in a Japanese woman with hereditary breast and ovarian cancer syndrome and who had a deleterious germline mutation of E1214X in BRCA1, but not a BRCA2 mutation. A pre-operative examination revealed multiple uterine leiomyomas but no adnexal mass. Robotic-assisted bilateral salpingo-oophorectomy together with hysterectomy was performed. A pathological examination identified serous tubal intraepithelial carcinoma in the right fallopian tube with no dissemination. Serous tubal intraepithelial carcinoma is implicated as an origin of invasive cancer of the fallopian tube with peritoneal dissemination; prophylactic salpingo-oophorectomy is currently the only method to identify this occult cancer. Our case demonstrated that risk-reducing salpingo-oophorectomy can detect occult cancers, including serous tubal intraepithelial carcinoma, thereby preventing future cancer development in the Japanese hereditary breast and ovarian cancer syndrome population.