Simultaneous metachronous renal cell carcinoma and skeletal muscle metastasis after radical nephrectomy

Renal cell carcinoma has a widespread and unpredictable metastatic potential and it can metastasize virtually to any site,1 even after a very long time from removal of the primary tumor.2 The most common sites for RCC metastasis are lungs, lymph nodes, liver, bones and adrenal glands.2,5 Skeletal muscle metastasis from RCC are extremely rare accounting 0.4% of all RCC metastasis.1e3 A limited number of cases regarding skeletal muscle metastasis from RCC have been described in the literature.4,5 We report a case of a clear cell renal carcinoma metastasis to the erector spinae muscle accompanied with metachronous RCC of the right kidney, approximately two years after left radical nephrectomy due to clear cell renal carcinoma. To our knowledge, this is the first case reported describing an RCC metastasis to the erector spinae muscle.