Myositis proliferans: diagnosis and therapy of a pseudosarcomatous soft tissue lesion.

Myositis proliferans is a soft tissue neoplasia with rare incidence. In the most cases, it is localized in the region of the neck, shoulder, pelvis and thigh. Due to its rapid growth and histological picture, the tumour may appear as a malignant neoplasia. We report the case of a 29-year-old woman suffering from an increasing painful swelling of the left proximal lower leg. Performed biopsies and histological examinations provided the diagnosis of myositis proliferans adjacent to the fibula, which responded to local resection and did not recur after 2 years. We show the importance of adequate diagnostic and therapeutic approach to avoid unnecessary and probably radical overtherapy of the patient.