Renal oncocytoma with a translocation t(9;11)(p23;q13).

We report a case of renal oncocytoma and confirm a tumor type specific translocation between chromosomes 9 and 11, that is t(9;11)(p23;q13q23). Each of the 45 cytogenetically analyzed metaphases of tumor cells showed a translocation of the long arm of chromosome 11 at q13 to chromosome 9 at 9p23 and to chromosome 20 at 20q13 that resulted in the following karyotype: 46,XX,der(11)ins(9;11)(p23;q13q23)ins(20;11)(q13;q23q25),del (22q13). Since genes encoding mitochondrial enzymes are clustered around the translocation site of chromosomes 11 and 20, they may have a role in the tumorigenesis of renal oncocytoma. In addition, if the development of oncocytomas shows different cytogenetic pathways the cytogenetic aberration of t(9;11)(p23;q12q13) can be of diagnostic help in differentiating a subset of oncocytoma from renal cell carcinoma.