Ann Coloproctol.  2019 Feb;35(1):47-49. 10.3393/ac.2018.03.15.

Anal Adenocarcinoma Can Masquerade as Chronic Anal Fistula in Asians

• Leong FQ
• Chan DK
• Tan KK

• KMID: 2446793
• DOI: http://doi.org/10.3393/ac.2018.03.15

Abstract

PURPOSE
Perianal adenocarcinoma arising from a chronic anorectal fistula is a rare condition for which the natural history and optimal management are not well established. For that reason, we conducted a retrospective analysis of 5 consecutive patients with a perianal adenocarcinoma arising from a chronic anorectal fistula managed at our institution from January 2014 to December 2015.
METHODS
The patients were identified from a prospectively collected colorectal cancer database that included all patients managed for colorectal cancer at our institution.
RESULTS
The median age at diagnosis was 64 years (range, 55-72 years). Magnetic resonance imaging (MRI) was the initial investigation for all patients and showed a hyperintense T2-weighted image. One patient underwent an abdominoperineal resection following neoadjuvant chemoradiotherapy and remained disease free during the 12-month follow-up. Three patients received neoadjuvant therapy with intent for surgery, but did not undergo surgery due to either worsening health or metastatic spread. One patient declined intervention. The median overall survival was 10.5 months (range, 2-19 months).
CONCLUSION
A high index of suspicion is required to make a clinical diagnosis of an anal adenocarcinoma arising from a chronic fistula. Histologic diagnosis must be achieved to confirm the diagnosis. Multimodal therapy with neoadjuvant chemoradiotherapy followed by abdominoperineal resection is the treatment of choice.

Keyword

Anal adenocarcinoma; Chronic inflammation; Anal fistula; Diagnosis

MeSH Terms

Adenocarcinoma*
Asian Continental Ancestry Group*
Chemoradiotherapy
Colorectal Neoplasms
Diagnosis
Fistula
Follow-Up Studies
Humans
Magnetic Resonance Imaging
Natural History
Neoadjuvant Therapy
Prospective Studies
Rectal Fistula*
Retrospective Studies