Genitourinary Malignancies in Transplant or Dialysis Patients: The Frequency of Two Newly Described 2016 World Health Organization Histopathologic Types.

BACKGROUND: The aim of this study was to revise the histopathologic types of neoplasias in the genitourinary tract and determine the frequency of 2 new entities included in the 2016 book of World Health Organization classification of renal tumors. It is not established so far whether these 2 recently described tumors are the most frequent in association with end-stage kidney disease.

METHODS: In a retrospective analysis, we revised the histopathologic type of 37 genitourinary tumors from 21 patients in dialysis and/or submitted to renal transplantation from 2003 to 2016 aiming to find the frequency of acquired cystic disease-associated renal cell carcinoma and clear cell papillary (tubulopapillary) renal cell carcinoma.

RESULTS: From the total of 37 tumors, 34 were from native end-stage kidneys, 1 from the pelvis of the transplant kidney, and 2 from the urinary bladder. The frequencies from native kidneys were: papillary carcinoma, 13/34 (38.2%); papillary adenoma, 9/34 (26.5%); acquired cystic disease-associated renal cell carcinoma, 4/34 (11.8%); oncocytoma, 3/34 (8.8%); conventional clear cell renal cell carcinoma, 3/34 (8.8%); and clear cell papillary (tubulopapillary) renal cell carcinoma, 2/34 (5.34%). The pelvis and urinary bladder tumors were high-grade urothelial carcinomas. The patients with urinary bladder tumors had been treated for polyomavirus infection.

CONCLUSIONS: The frequencies of acquired cystic disease-associated renal cell carcinoma and clear cell papillary renal cell carcinoma were 11.8% and 5.9%, respectively. However, the spectrum of adenoma/carcinoma papillary tumors composed the majority, 64.7%, of tumors.