title: Primary peritoneal low-grade serous carcinoma forming a mass in the colon mimicking a colonic primary carcinoma: a case report.
abstract: Primary carcinomas of Müllerian origin involving the colon is not an uncommon phenomenon, with most cases reportedly associated with endometriosis. On the other hand, a primary peritoneal low-grade serous carcinoma presenting as a dominant mass in the colon and causing clinical symptoms mimicking a primary colonic carcinoma has not been reported in the literature to the best of the authors' knowledge. A case of a 66-year-old female patient who presented clinically with rectal bleeding and a rectosigmoid mass is described. The final histologic examination revealed a peritoneal low-grade serous carcinoma forming a dominant mass in the rectosigmoid colon. Of particular interest was a microscopic spectrum of serous epithelial proliferation in the peritoneal cavity and lymph nodes with morphologic features reminiscent of non-invasive and invasive implants in ovarian borderline serous tumors, which most likely denoted the precursors of the tumor in the colon.
authors.affiliation: Department of Pathology, Florida Hospital Orlando, Orlando, Florida 32803, USA. trannguyentienanh@hotmail.com
authors.forename: T A
authors.initials: TA
authors.lastname: Tran
authors.forename: R W
authors.initials: RW
authors.lastname: Holloway
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000473:pathology*; D018284:Cystadenocarcinoma, Serous / Q000473:pathology*; D005260:Female; D006801:Humans; D060787:Neoplasm Grading; D010534:Peritoneal Neoplasms / Q000473:pathology*