Mycosis fungoides (MF) is a malignant lymphoma that arises in the skin and subsequently may involve lymph nodes and viscera as part of the natural course of the disease. The disease has distinct histologic characteristics that may be recognized in extracutaneous tissues. A patient who had MF with ulcerating cutaneous nodules is presented herein. Death resulted from perforation of the small bowel involved by the disease and consequent peritonitis.