The simultaneous occurrence of different histological types of adjacent neoplasms in the same organ is called a collision tumour, and rarely occurs in the kidney.
A 63-year-old female presented to the urology department with a 1-month history of a painless hematuria. The computed tomography scans of the abdomen revealed 2 heterogeneous incidental right renal masses. The patient underwent radical nephrectomy including lymphadenectomy without adjuvant therapy. Histopathological examination showed a type 2 renal collision tumour of the papillary renal cell carcinoma with eosinophilic cytoplasm and pseudostratified nuclei on papillary cores, and chromophobe renal cell carcinoma characterized by large polygonal cells with transparent reticulated cytoplasm and prominent cell membranes, which exhibited sarcomatoid transformation in the local area. Routine follow-up demonstrated no local or distant metastasis signs of recurrence at 20 months.
Written by:
Zhang Z, Min J, Yu D, Shi H, Xie D. Are you the author?
Department of Urology, the Second Affiliated Hospital of Anhui Medical University, Anhui Province, China.
Reference: Can Urol Assoc J. 2014 Jul;8(7-8):E536-9.
doi: 10.5489/cuaj.1811
PubMed Abstract
PMID: 25210558