Rarely a patient with a chronic anorectal fistula may develop a perianal mucinous adenocarcinoma. The diagnosis may be delayed if the patient does not undergo active surveillance with biopsy.
Features:
(1) The patient has a chronic anorectal fistula, typically in a patient with Crohn’s disease.
(2) The patient may have a history of sepsis related to the fistula (perianal sepsis).
(3) Paget’s disease in the overlying skin may precede the tumor.
(4) The patient develops a mucinous adenocarcinoma arising from along the fistula tract or within an abscess cavity.
(5) Metastases typically go to the inguinal lymph nodes.
The tumor appears to arise as an extramucosal adenocarcinoma with no intestinal primary lesion.
Management typically involves an abdominoperineal resection with block resection of inguinal lymph nodes if involved followed by chemoradiation.
To read more or access our algorithms and calculators, please log in or register.
