Renal Cell Carcinoma in Young Adults: A Study of 130 Cases and a Review of Previous SeriesLópez J.I. · Moreno V. · García H. · Antón I. · Robles A. · Oñate J.M. · Baños Á. · Escandón J. · Ugalde A.
Departments of Pathology,aHospital de Cruces, Basque Country University (EHU/UPV), Barakaldo, bHospital de Txagorritxu, Basque Country University (EHU/UPV), Vitoria-Gasteiz, cHospital 12 de Octubre, Complutense University, Madrid, dPOVISA, Vigo, eHospital de Valme, University of Sevilla, Sevilla, fHospital del Rio Hortega, University of Valladolid, Valladolid, gHospital General Yagüe, Burgos, hHospital Peset, University of Valencia, Valencia, and iHospital de Basurto, Basque Country University (EHU/UPV), Bilbao, Spain
Objective: To characterize a large series of renal cell carcinomas (RCCs) in young patients and to compare the data obtained to previously published data. Patients and Methods: A total of 130 RCCs diagnosed in patients <40 years of age were collected from 9 different hospitals in Spain. Cases were re-evaluated following the diagnostic criteria of the 2004 WHO classification of renal tumors. Results: Histologically, tumors were classified as clear cell (50.7%), papillary (8.5%), chromophobe (14.6%), unclassified (16.9%) and clear cell papillary (9.3%) RCCs. Organ-confined disease (OCD) was detected in 83.6% of the cases. Tumor size and Fuhrman’s grade were statistically correlated (Spearman’s ρ = 0.391). CD10 (p = 0.000), CK7 (p = 0.000), CD15 (p = 0.016), CD117 (p = 0.000), 34βE12 cytokeratin (p = 0.034) and e-cadherin (p = 0.000) immunostaining significantly differentiated the five histological categories. Conclusions: OCD was more common in young RCC patients. The clear cell phenotype accounted for only 50% of RCCs in this age group, with an increasing number of chromophobe and unclassified RCCs. Clear cell RCCs with a papillary growth pattern accounted for a significant proportion of the cases.