Unusual Case of Coexisting Renal Malignancies: Mucinous Tubular and Spindle Cell Carcinoma Kidney With Sarcomatoid Dedifferentiation. jkcvhl [Internet]. 2016 May 31 [cited 2026 May 3];3(2):8-13. Available from: https://mail.jkcvhl.com/index.php/jkcvhl/article/view/51