Cytogenetic features, clinical significance and prognostic impact of type 1 and type 2 papillary renal carcinoma.

The purpose of this paper is to evaluate the clinical, pathologic, and cytogenetic features, as well as the disease-free survival in patients with papillary renal cell carcinoma (PRCC) subdivided into types 1 and 2, according to the definition given by Delahunt and Eble. The clinical, surgical, and follow-up data for the PRCC cases treated since 1995 were taken from an institutional database. The samples were revised by an experienced pathologist, who subdivided them into types 1 and 2. The data from the cases in which the tumor karyotype was available were analyzed. Out of 1,150 patients surgically treated for renal cancer, 132 cases of PRCC were detected (prevalence 11.5%), 57 with type 1 and 75 with type 2, followed for a mean period of 50 months. Tumor diameter, peri-renal tissues, as well as venous invasion, lymphnodal, and distant metastasis were highlighted to be distributed with a significant difference between the two groups, which indicated higher aggressiveness in type 2 cases. Survival analysis has showed a significantly higher-progression risk and a shorter disease-free survival in type 2 cases. An evaluable tumoral karyotype was obtained in 26 cases. An overlapping distribution was detected in chromosomes 7, 17, 12, 16, and 20, while some alterations in chromosomes 10, 5, 6, 11, 15, 18, 22, and 8 appeared as typical of type 2 cases. In conclusion, types 1 and 2 PRCC have different pathologic and cytogenetic features and a radically different biologic behavior d indolent in type 1 and aggressive in type 2.