title: A unique retrorectal tumor with neuroendocrine differentiation: case report and review of the literature.
abstract: Retrorectal or presacral tumors are very rare. We report a unique case of a retrorectal tumor with neuroendocrine differentiation, consisting of high- and low-grade components. A 53-year-old woman treated for a perianal abscess at another clinic was referred to our hospital for continued anal pain. Digital rectal examination identified a soft tumor with a smooth surface in the lower rectum. Pelvic computed tomography and magnetic resonance imaging detected a large cystic tumor measuring 8 cm in diameter in the retrorectal space of the pelvis. The border between the tumor and rectal wall, levator ani and vaginal wall was obscure. Fine-needle aspiration cytology was highly suggestive of carcinoma. Abdominoperineal resection was performed, and the tumor was histologically diagnosed as a neuroendocrine carcinoma based on immunohistochemical staining. No previous case has been reported with cystic growth of a neuroendocrine carcinoma in the retrorectal space.
authors.affiliation: Department of Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 3290498, Japan. 96084sm@jichi.ac.jp
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Misawa
authors.forename: Hisanaga
authors.initials: H
authors.lastname: Horie
authors.forename: Takehiko
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kumano
authors.forename: Alan T
authors.initials: AT
authors.lastname: Lefor
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yasuda
mesh_terms: D003113:Colonoscopy; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery
keywords: cystic growth; neuroendocrine; retrorectal tumor