Colorectal carcinoma metastatic to skeletal muscle

Skeletal muscle is one of the most unusual sites of metastasis from any malignancy. We report on a case of skeletal muscle metastasis from colonic carcinoma, and review seven previously reported cases. The patient was a 66-year-old man who exhibited a painful metastatic mass in the right major teres muscle six months after surgery for colonic carcinoma. He underwent three operations and one course of arterial infusion chemotherapy, but died of carcinoma after two years and seven months. In seven previous cases and in the present case (3 males and 5 females, aged between 30 and 75 years), the sites of the primary lesion and metastatic lesion in skeletal muscle were diverse. The interval between primary carcinoma and relapse ranged from synchronous to 5 years. Spontaneous pain in the recurrent region was a characteristic symptom. Surgical removal of the metastatic lesions relieved pain. Prognosis was considered poor. However, complete resection of the metastatic lesion at a time when no other recurrent lesions were present might have cured the patient.