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.