Melanoma of the rectum: A rare entity

Figure 1 Histopathological examination of a biopsy taken at rectosigmoidoscopy showed the tumour to be a leiomyosarcoma (HE, × 100).

Figure 2 MRI-rectum showing a tumour just behind the anal verge.

Figure 3 Histopathological examination of the abdomino-perineal resection (S-100 Positive, x 200). S-100 staining performed with an automatic system (Benchmark XT, Ventana Systems). Diffuse expression of S-100 staining typical for melanoma. In leiomyosarcoma, S-100 is never expressed.