Granular cell tumours are uncommon soft tissue tumours that could be located anywhere throughout the body. Most of time they are benign but the diagnosis of malignancy is difficult to establish on histology: this is why the therapeutic decision is not easy to take in particular for some locations. We report the case of a 18-year old man: he presented, in the perianal region, a granular cell tumour of uncertain malignant potential (so far the first case described in the literature) for which we decided a conservative surgical treatment that failed.