title: Anal Canal Adenocarcinoma in a Patient with Longstanding Crohn's Disease Arising From Rectal Mucosa that Migrated From a Previously Treated Rectovaginal Fistula.
abstract: BACKGROUND This study reports the pathogenesis of anal canal adenocarcinoma in a patient with longstanding Crohn's disease (CD). CASE REPORT A 50-year-old woman with a 33-year history of CD presented with perianal pain of several months' duration. She had been treated surgically for a rectovaginal fistula 26 years earlier and had been treated with infliximab (IFX) for the previous 4 years. A biopsy under anesthesia revealed an anal canal adenocarcinoma, which was removed by abdominoperineal resection. Pathological examination showed that a large part of the tumor consisted of mucinous adenocarcinoma at the same location as the rectovaginal fistula had been removed 26 years earlier. There was no evidence of recurrent rectovaginal fistula, but thick fibers surrounded the tumor, likely representing part of the previous rectovaginal fistula. Immunohistochemical analysis using antibodies against cytokeratins (CK20 and CK7) revealed that the adenocarcinoma arose from the rectal mucosa, not the anal glands. CONCLUSIONS Mucinous adenocarcinoma can arise in patients with CD, even in the absence of longstanding perianal disease, and may be associated with adenomatous transformation of the epithelial lining in a former fistula tract.
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Maejima
authors.affiliation: Advanced Surgery Center, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kono
authors.affiliation: Inflammatory Bowel Disease Center, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Fumika
authors.initials: F
authors.lastname: Orii
authors.affiliation: Inflammatory Bowel Disease Center, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Maemoto
authors.affiliation: Inflammatory Bowel Disease Center, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Furukawa
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Wang
authors.initials: W
authors.lastname: Liming
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kasai
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Fukahori
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Mukai
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Daitaro
authors.initials: D
authors.lastname: Yoshikawa
authors.affiliation: Department of Surgery, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Karasaki
authors.affiliation: Department of Imaging Radiology, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Saito
authors.affiliation: Department of Pathology, Sapporo Higashi Tokushukai Hospital, Sapporo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagashima
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D001003:Anal Canal / Q000000981:diagnostic imaging*; D000714:Anastomosis, Surgical / Q000009:adverse effects; D001005:Anus Neoplasms / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D001706:Biopsy; D003082:Colectomy; D003113:Colonoscopy; D003424:Crohn Disease / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging*; D008875:Middle Aged; D012006:Rectovaginal Fistula / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D012007:Rectum / Q000601:surgery; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014621:Vagina / Q000601:surgery