Coexistence of Different Histotypes of Renal Carcinoma: Our Experience and Literature Review

Abstract

The coexistence of multiple, synchronous primary tumors of different histology within the same kidney is a rare condition. We report herein a series of five patients with two tumors of different histology involving synchronously the same kidney. Materials and Methods We reviewed the pathology reports of a series of 381 patients who underwent surgery for primary renal tumors at our institution from 2000 to 2007. In the files of all patients with synchronous tumors of different histology, special attention was given to the results of imaging studies. Results Five out of 381 patients (1.37%) had coexistence of two primary tumors of different histology within the same kidney. Four patients had ultrasonography as the first imaging procedure, one patient had ultrasonography as the second imaging procedure; all had preoperative CT of the abdomen. Both lesions were detected by preoperative CT in 4/5 of the cases; in the remaining one, the smaller lesion was not visible, even in retrospect. Conclusions The coexistence of multiple and synchronous primary tumors of different histology within the same kidney has been only rarely described. To the best of our knowledge, in literature there are only case reports with the exception of a case of renal oncocytoma with evolving papillary RCC. We believe that this condition could be more frequent if the radiologist and the anatomopathologist try to find it.