A Cytogenetic and Morphologic Study

A detailed G-banded chromosome analysis was performed in primary cell cultures obtained from two renal oncocytomas. Both tumors were characterised by clonal chromosome aberrations. One had a stemline karyotype 45,X,-X,rcp(8;19),der(l3)t(X;13) and several sidelines with variant additional aberrations. The chromosome analysis of the other neoplasm revealed a pseudodiploid stemline 46,XY,del( lq),der(l3)t( 1;13) and cells with normal karyotype; both types of cells showed several telomeric associations of chromosomes, formed mostly by smaller chromosomes. The chromosome pattern of oncocytomas is discussed in comparison with the cytogenetics of renal cell carcinomas. Cancer 59:2071-2077, 1987. NCOCYTOMAS, including renal oncocytomas, have 0 long been regarded as a separate entity by German pathologists. Klein et al. published the first systematic review of renal oncocytomas in English literature, terming them “proximal tubular adenomas of the kidney with socalled oncocytic features.” A significant difference was found between renal cell carcinomas and renal oncocytomas with respect to macroscopic and microscopic appearance, as well as clinical behavior. The authors suggested that renal oncocytoma be regarded a distinct entity and a benign tumor. Following this article, several publications appeared that supported this ~ontention.~-~ Observations of a number of renal oncocytomas showing signs of malignancy, i. e., local invasion and venous spread, however, in addition to data on occasional malignant oncocytomas occurring in other organs, suggest that renal oncocytomas must be considered potentially maligMost malignant tumors are characterized by chromosome aberrations, and some types of human malignant diseases are associated with specific, consistent chromosome changes. l7 Clonal chromosome aberrations also are