A 62-year-old woman was seen at the hospital for close exploration because her stool examination was positive at a medical checkup. Anoscope and digital examination revealed an elastic-hard and ill-movable submucosal tumor in the anus at the 3 o'clock direction. Contrast enhanced CT scan of the abdomen showed a tumor with enhancement. Since a possibility of malignant tumor could not be ruled out, the tumor was removed through the transanal approach. Histopathological studies of the removed material revealed tumor cells with granular or bright and broad cytoplasm and oval-shaped nuclei, which were S-100 protein positive immunohistochemically. The difinite diagnosis of granular cell tumor of the anus was made.
Granular cell tumors are benign neoplasms of Schwann cell derivation. These tumors develop in any parts of the body, but are most often seen in subcutoneous stractures of the chest wall, breast and neck. They rarely appear in the gastroinstestinal tract, especially in the anus. Since our experience with a case of granular cell tumor appeared as a submucosal tumor in the anus in thought to be of value, the case is presented here.