Sigmoid colon metastasis from sarcomatoid renal cell carcinoma

The sarcomatoid histological type of renal cell carcinoma is a clinically aggressive variant of parenchymal tumor, typically resistant to systemic treatment. We report the case of a 65-year-old female patient who had undergone a left radical nephrectomy for a sarcomatoid renal cell carcinoma together with enucleation of a mass of the right kidney and a contralateral nodule diagnosed as clear cell carcinoma. One year later lung, adrenal and sigmoid colon metastases from sarcoma-told renal cell carcinoma were detected and the patient was started on systemic immunotherapy with interteukin-2 and interferon-α. Computed tomography showed marked disease progression and the patient died 3 weeks later. Sigmoid colon metastasis from a primary sarcomatoid renal cell carcinoma has never been described in the literature.