Squamous dysplasia of the rectum in a patient with ulcerative colitis treated with 6-mercaptopurine.

Human papilloma virus (HPV) has been found to be a precursor and risk factor for both cervical and anal dysplasia. Cervical dysplasia, which is the precursor to carcinoma, is associated with immunosuppression from a variety of causes; reports of anal dysplasia associated with immune suppression exist as well. A recent study published in abstract form only demonstrated that women with inflammatory bowel disease (IBD) had high rates of cervical dysplasia and that those on immune suppressants had even higher rates of dysplasia. We report a case of a 50-year-old woman with refractory ulcerative colitis chronically treated with 6-mercaptopurine that developed severe squamous dysplasia of the rectum. The dysplastic mucosa was found to be positive for p16 (associated with high-risk HPV) after immunostaining. A total colectomy was performed. This case highlights the importance of immune suppression in the development of dysplasia of the anus/cervix secondary to HPV infection.