title: Primary and secondary adenocarcinomas associated with anal fistulae.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the clinical features, pathology, and etiology of adenocarcinoma in patients with anal fistulae.
  
  
  METHODS
  We identified seven patients diagnosed with adenocarcinoma associated with anal fistulae from a retrospective chart review.
  
  
  RESULTS
  Five patients were diagnosed with primary adenocarcinoma associated with anal fistulae. Two patients were diagnosed with secondary adenocarcinoma associated with anal fistulae originating from rectal cancer on the proximal side. The primary adenocarcinomas included cancers arising from long-standing anal fistulae fulfilling established diagnostic criteria in two patients, and cancer arising from short-duration anal fistulae in three patients. Excision of the fistula was performed based on the initial diagnosis of the anal fistula for all five patients. Increased suspicion of cancer was due to the existence of gelatinous material in the anal fistula in three patients and induration in the resected specimens in two patients. The etiologies of the secondary adenocarcinomas associated with anal fistulae included implantation in the anal fistula from rectal cancer and fistula formation originating due to the progression of rectal cancer.
  
  
  CONCLUSIONS
  Anal fistulae are commonly seen in the coloproctology clinic, but special attention to similar conditions associated with malignant disease is needed.
authors.affiliation: Utsunomiya Coloproctology Clinic, 1-1-7 Daikan-cho, Utsunomiya, Tochigi, 320-0867, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yamada
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Miyakura
authors.forename: Koji
authors.initials: K
authors.lastname: Koinuma
authors.forename: Hisanaga
authors.initials: H
authors.lastname: Horie
authors.forename: Alan T
authors.initials: AT
authors.lastname: Lefor
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Fukushima
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Oyama
authors.forename: Yuta
authors.initials: Y
authors.lastname: Nemoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Azuma
mesh_terms: D000230:Adenocarcinoma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012003:Rectal Fistula / Q000209:etiology* / Q000473:pathology / Q000601:surgery; D012004:Rectal Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery