Painful Leg: A Very Unusual Presentation of Renal Cell Carcinoma Case Report and Review of the Literature

Introduction: An unusual case of isolated synchronous solitary gastrocnemius muscle metastases of renal cell carcinoma (RCC) is reported. A review of the literature with particular emphasis on diagnostic and therapeutic approaches is also included and discussed. Material and Methods: A complete review of the English literature using MEDLINE was performed between 1979 and 2008 on RCC and skeletal muscle metastasis. Results: Overall, 23 cases have been reported to have skeletal muscle metastasis by RCC. We report a 58-year-old male patient who was admitted to the orthopedics clinic with a painful left leg swelling. Physical examination revealed a hard mass on his posterior left leg. Magnetic resonance imaging demonstrated a 2 x 4 cm sized mass. Incisional biopsy revealed surprisingly clear cell RCC metastasis. Abdominal radiologic studies demonstrated a 7 x 7 x 6 cm sized left renal mass. Left radical nephrectomy was performed with additional excision of the metastatic mass with negative surgical margins. External radiotherapy to the left leg and 3 cycles of Hannover immunochemotherapy were administered thereafter. The patient was disease-free at the first year of follow-up. Conclusions: Presentation of RCC as a solitary metastasis in the skeletal muscle is a very unusual and poorly documented site of metastasis which can be treated successfully by excision of the metastasis and renal tumor with additional local radiotherapy and immunochemotherapy. Copyright (C) 2009 S. Karger AG, Basel