Multiple Muscle Metastases of the Renal Cell Carcinoma After Radical Nephrectomy

Skeletal muscle is a very rare location for the metastasis of renal cell carcinoma. We report a 48-year-old man with multiple metastases in skeletal muscles 4 years after right radical nephrectomy was carried out for grade III renal cell carcinoma. The tumors located in the right psoas, paravertebral, and gluteus medius muscles. We performed magnetic resonance imaging for detection metastatic lesions in our patient. In this case report, we discuss the characteristics of these metastatic lesions on magnetic resonance imaging.Key words: Renal cell carcinoma, Multiple muscle metastases, MR imagingRenal cell carcinoma (RCC) has widespread and unpredictable metastatic potential, even after curative nephrectomy is performed.^1–3 RCC is able to metastasize to virtually any site. The most common sites of metastatic RCC are the lungs, lymph nodes, bones, liver, adrenal glands, and brain.^1,4 In several autopsy series, about 0.4% of cases with RCC had skeletal muscle metastases.² Making a diagnosis of metastatic RCC to the skeletal muscle is challenging, because the site is unpredictable, in addition to it being rare, a recent review of the literature revealed some cases.^2–5In our study, we report a case of RCC with metastases to the right psoas, paravertebral, and gluteus medius muscles after 4 years right side radical nephrectomy. We wish to emphasize the magnetic resonance imaging (MRI) features of metastatic RCC to the skeletal muscles.