Metastatic carcinoma to skeletal muscle. A report of 15 patients.

The records of 15 patients with metastatic carcinoma to skeletal muscle treated between 1979 and the present were reviewed. Fourteen patients were referred with a diagnosis of soft tissue sarcoma and one with suspected infection. There was a previous diagnosis of carcinoma in eight patients but seven patients had no prior diagnosis of a known malignancy. Primary tumors were lung (eight), melanoma (two), gastrointestinal (one), kidney (one), and bladder (one). No primary tumor could be identified in two patients. Local control of metastatic lesions was achieved by radiotherapy in 11 patients as an initial measure. Two patients underwent wide excision and one declined treatment for local tumor control. Eight patients died within 12 months of presentation and survival analysis indicated a 25% overall survival at 60 months. Two patients remained free of disease at 132 months and 72 months. From this study and a review of 52 cases reported in the literature, the authors are unable to find any clinical or radiographic characteristics that distinguish metastatic carcinoma to muscle from soft tissue sarcomas. Surgical resection can be reserved for cases in which radiation does not provide local control.