PURPOSE:This study was conducted to report a rare case of anorectal pathology.METHODS:We report a case of perianal lymphoma in a nonimmunocompromised, heterosexual patient and review the literature.RESULTS:A 67‐year‐old white male was found to have an ulcerated posterior anal mass. Biopsy revealed large cell lymphoma, B cell type, immunoblastic. There was no disseminated disease. The patient denied any homosexual activity and was HIV negative. There was complete resolution with chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone), and he remained disease free for six years.CONCLUSIONS:Rare anorectal pathology may mimic common conditions. Biopsies should be taken to rule out malignancy.