MYOSITIS PROLIFERANS - A PSEUDOSARCOMATOUS SOFT-TISSUE DISEASE

Myositis proliferans is a reactive, intramuscular soft tissue disease characterized by fibroblast and myofibroblast proliferation, showing s imilarities to the phase-like development seen in the general patholog y of wound healing and hypertrophic scars. Immunohistochemically,a com bined expression of vimentin and alpha-sm actin is seen in the spindle -shaped cell formations. The decisive histological preparation is supp orted by immunohistochemical techniques, especially in the differentia tion from sarcoma. If a definite diagnosis is made, incomplete excisio n may suffice.