[Muscle metastases: ultrasonic and x-ray computerized tomographic aspects. Apropos of 9 cases]

Clinical, ultrasound and CT scan examinations were carried out in 9 patients with secondary muscle lesions. All muscles can be affected but there was a marked predominance of psoas lesions (6 of the 9 cases). Two contrasting clinical pictures are seen. Secondary muscle tumors can occur during evolution of a known treated cancer (5 of the 9 cases), revealed usually by large, rarely painful, mass. CT scan imaging shows a heterogeneous mass taking up contrast and often partially necrotic, the lesions appearing hypoechogenic or heterogeneous on ultrasound examination. Certain lesions can be totally necrotic. In some cases (4 of the 9 patients) the muscle metastases revealed the presence of a tumor. Symptomatology may be atypical and lead to a delay in diagnosis. Fine needle puncture biopsy can detect the secondary origin of the muscle lesion and also the primary tumor site (4 out of 9 cases), bronchopulmonary and colon cancer predominating. Images are however non-specific and in the absence of NMR imaging the muscle or lymph node metastases can be confused, although this has no practice consequences since treatment is identical.