Anti-desmin detects a protein that is expressed by cells of normal smooth, skeletal, and cardiac muscles. It has been proposed that desmin is primarily located at or near the periphery of Z lines in striated muscle fibrils. In smooth muscle, desmin interconnects cytoplasmic dense bodies with membrane bound dense plaques. Leiomyomas, leiomyosarcoma, rhabdomyomas, rhabdomyosarcoma, and perivascular cells of glomus tumors of the skin all react with anti-desmin. The myogenic components/derivation of tumors are demonstrated using this antibody. Desmin can also be present in myofibroblasts and be focally positive in desmoid fibromatosis.