Cytogenetic analysis of a series of 13 renal oncocytomas.
OBJECTIVE
Only about 50 renal oncocytomas have been studied cytogenetically. They fall into 3 categories, namely 1-normal karyotype, 2-monosomy 1, often with Y chromosome loss, and 3-structural abnormalities of 11q13. Additional abnormalities may occur with transformation to chromophobe renal cell carcinoma, although exactly which one is unclear. We expanded the oncocytoma data base to shed light on changes that characterize transformation.


METHODS
A total of 14 oncocytomas from 12 patients were collected in 2(1/2) years. One tumor failed to grow but 13 were successfully karyotyped.


RESULTS
Seven tumors (53.8%), including 2 from 1 kidney, had normal karyotypes or abnormalities characteristic of normal kidney tissue. A total of 6 tumors from 5 individuals (46.2%) had chromosome 1 abnormalities. Monosomy 1 was detected in 2 single tumors and in both tumors in a bilateral case. Structural anomalies resulting in loss of the short arm of chromosome 1 were found in an additional 2 patients. Other abnormalities, including Y chromosome loss and monosomy 14, were observed but no abnormalities of 11q13 were seen.


CONCLUSIONS
Our series confirms that 1p loss is the most common anomaly in oncocytoma. Additional studies are required to understand the transformation potential of this usually benign tumor, identify the putative 1p tumor suppressor gene and determine whether karyotypically normal tumors have molecular abnormalities of 1p.
Lindgren
Valerie
V
Department of Pathology, University of Illinois at Chicago, 60612, USA. lindgren@uic.edu
Paner
Gladell P
GP
Omeroglu
Atilla
A
Campbell
Steven C
SC
Waters
W Bedford
WB
Flanigan
Robert C
RC
Picken
Maria M
MM
D018249:Adenoma, Oxyphilic / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged