A rare case of granular cell tumor of the anal region: diagnostic difficulty to masses in the anal area.

Granular cell tumor may be located anywhere in the body; however, the gastrointestinal tract is infrequently involved and anal granular cell tumors are extremely rare. We report herein a rare case of granular cell tumor in the anal region. In the current case, a 66-year-old Japanese woman was found to have a polypoid lesion in the anus with hemorrhoids. The mass detected as an anal polypoid lesion with ulceration was resected and diagnosed as granular cell tumor by histologic examination. Granular cell tumor of the anal region is rare, and benign perianal polypoid lesions are relatively uncommon clinical findings. They might present diagnostic challenges to surgeons and pathologists. Awareness of the differential diagnosis of granular cell tumor and careful microscopic examination might allow proper management and diagnosis.