Mucinous adenocarcinoma arising from chronic perianal fistula mimicking horseshoe abscess

BMJ Case Rep. 2018 Apr 5:2018:bcr2017223063. doi: 10.1136/bcr-2017-223063.

Abstract

Perianal fistulae are commonly seen clinical entity. Development of malignancy within a perianal fistula is rare. Even rarer is the development of mucinous adenocarcinoma in a chronic fistula-in-ano. Only a handful of such cases have been reported in the past. A case of mucinous adenocarcinoma arising in chronic perianal fistula in a 34-year-old woman is being described. She presented with complaints of perineal fullness, pain and recurrent pus discharge from perianal fistula for 4 years. On radiological workup, a large solid-cystic pelvic mass was seen in relation to the fistula. On MRI, the lesion was mimicking a large horseshoe abscess. Transrectal ultrasound-guided biopsy and subsequent histopathological examination confirmed the presence of mucinous adenocarcinoma with tumour cells immunopositive for CK7 and CK20.

Keywords: colon cancer; gastrointestinal surgery; radiology; radiology (diagnostics); surgical oncology.

Publication types

  • Case Reports

MeSH terms

  • Abscess / pathology
  • Adenocarcinoma, Mucinous / diagnosis*
  • Adenocarcinoma, Mucinous / therapy
  • Adult
  • Anus Neoplasms / diagnosis*
  • Anus Neoplasms / therapy
  • Chemoradiotherapy*
  • Chronic Disease
  • Diagnosis, Differential
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Neoadjuvant Therapy*
  • Perineum / pathology*
  • Rectal Fistula / complications
  • Rectal Fistula / diagnosis*
  • Rectal Fistula / therapy
  • Treatment Outcome