Inflammatory myofibroblastic tumor of the skin.

We report a case of inflammatory myofibroblastic tumor (IMF) of the skin in a female with a history of Wegeners granulomatosis. The patient had a painless, erythematous, and indurated lesion of the left elbow. The resected specimen revealed a 4 cm x 3 cm nodule involving the entire dermis and superficial portions of subcutis with a stellate profile at scanning magnification. There were spindle cells in fascicles and whorls and a mixed inflammatory cell infiltrate of plasma cells, lymphocytes, neutrophils, and eosinophils. The spindle cells were immunoreactive for vimentin, muscle specific actin, and smooth muscle actin. The polyclonal and polymorphous nature of the inflammatory cells was confirmed by immunohistochemical studies. This is the first case of IMF of the skin documented by immunostaining.