The establishment, characterization, and tumorigenicity of a new epithelial cell line (UOK 257) derived from human renal carcinoma of an individual with Birt-Hogg-Dubé (BHD) syndrome are reported. Unlike other established renal tumor cell lines from sporadic renal cell carcinoma, this is the first established renal tumor cell line of BHD, an inheritable neoplastic syndrome. The isolated tumor cells display loss of contact inhibition in vitro, and produce subcutaneous tumors in mouse xenografts. Histopathologic, ultrastructural, and cytogenetic characterizations of the established tumor cells are reported. Cytogenetic analysis using spectral karyotyping on UOK 257 cells revealed 17p loss and a near-triploid and aneuploid karyotype with multiple fluorescence in situ hybridization analysis using a locus-specific gene probe for MYC. The result demonstrates that the established tumor cells consist of two cell populations, one containing four and one containing five copies of the MYC oncogene.