Collecting duct of Bellini renal carcinoma with psoas muscle recurrence: A case report and review of literature.

Collecting duct carcinoma (CDC) is a rare type of renal carcinoma with an aggressive course and poor treatment response. Up to date, there are only few reports of CDC, which may be due to unrecognized or unfamiliarity of its features and characteristics. We report a case of CDC in a 63-year-old male who initially presented with localized disease, and developed psoas muscle metastasis 15 months after partial nephrectomy with good surgical margins.