del(3p)(p13p21) in renal cell adenoma and del(4p)(p14) in bilateral renal cell carcinoma in two unrelated patients with von Hippel-Lindau disease.

Karyotype analyses of renal cell adenoma in one patient and bilateral renal cell carcinomas (RCC) in another unrelated patient have been performed. Both patients belonged to families with von Hippel-Lindau disease (vHL). In the adenoma, we found a clonal del(3)(p13p21) and a small clone of two cells with an additional del(14)(q13). This result indicates that the same region that is often deleted in RCC may also be deleted in a renal cortical adenoma. This finding may facilitate the localization of a tentative renal cell adenoma/carcinoma tumor suppressor locus. In the tumors from the patient with bilateral carcinomas we found a clonal del(4)(p14) on one side and on the other a del(4)(p14) together with del(14)(q13). In this case, there was no detectable 3p defect in the tumors. This result raises the question whether an alternative/additional locus on chromosome 4p may be involved in the RCC/vHL syndrome. Constitutional karyotypes were in both cases normal.