Anal carcinoma occurring in Crohn's disease patients with chronic anal fistula.

This paper reports six patients with perianal Crohn's disease (CD), who developed anal cancer in chronic anal fistulas. Tumors have been often diagnosed at an advanced stage and had a worse prognosis than cancers arising in the general population as tumor symptoms may mimic symptoms of CD, resulting in delay in diagnosis. Patients with perianal CD should undergo a careful surveillance program for ano-rectal carcinoma, including routine biopsy of any suspected lesion. When malignancy is found, an aggressive surgical approach and complementary therapy are mandatory.