[Primary leiomyosarcoma of the bone].

In a 52-year-old female patient and a 50-year-old patient with a malign tumor of the right distal femur (stage IIIb) respectively the left distal tibia (stage Ia according to Enneking), the extremely rare primary leiomyosarcoma of the bone was diagnosed. The mortality of the primary leiomyosarcoma of the bone is 50%, the mean survival time after diagnosis is 3.4 years. Diagnosis of a primary leiomyosarcoma of the bone is only possible after a secondary leiomyosarcoma has been excluded as well as by histopathological including immunohistochemical examination. The operative procedure is the therapy of choice. A neoadjuvant and/or adjuvant radio- or chemotherapy can be useful.