Primary collision renal tumor of papillary renal cell carcinoma within an oncocytoma: emergency presentation of a rare entity Posted on March 4, 2019August 22, 2019 by admin CASE REPORT Hippokratia 2017, 21(2):105-107 Paschos KA, Chatziaggelou A, Chatzigeorgiadis A Department of General Surgery, General Hospital of Drama, Drama, Greece