The association of serous tubal intraepithelial carcinoma with gynecologic pathologies and its role in pelvic serous cancer

•We investigated the possible shared primary sites of pelvic serous carcinomas (PSC).•STIC was mostly located at the fimbria, contacting the peritoneal cavity and ovaries.•Findings suggested fallopian tubes as the primary sites, but further studies are needed to investigate the accurate carcinogenesis.

ObjectivesPossible primary sites of pelvic serous cancers are, fallopian tubes, ovaries or peritoneum. Recent studies have revealed that a portion of these tumors originates from serous tubal intraepithelial carcinoma (STIC) at the distal end of fallopian tubes. In this study, the association of STIC with pelvic serous carcinomas and the pathologic parameters that indicate the tubes as the primary site were assessed.MethodsIn total, 495 pairs of fallopian tubes obtained via total abdominal hysterectomy and bilateral salpingo-oophorectomy between 2011 and 2013 were examined according to SEE-FIM protocol. Hematoxylin and eosin-stained slides were examined by pathologists. Suspicious areas were immunostained with p53 and Ki-67 to diagnose STIC precisely.ResultsOf the 495 cases, 110 cases were malignant. Among 34 cases of non-uterine serous carcinomas, 13 were diagnosed with STIC. STIC was located at the fimbrial end of the fallopian tubes in 12 cases. No STIC was identified in the gynecologic malignancies other than non-uterine serous pelvic carcinomas and benign gynecologic pathologies. Comparison of the ovarian and tubal cancer cases with and without STIC did not reveal a factor that helps to define the primary site. STIC was an important factor associated in a higher portion of the cases with bilateral ovarian cancer.ConclusionThe role of STIC in carcinogenesis continues to be discussed as it is unknown whether STIC is the precursor lesion or just associates with the malignancies. Discovering the accurate precursor lesions and tumor carcinogenesis is essential to prevent these malignancies and to develop early diagnostic methods.