Cytogenetic and molecular genetic studies of a patient with atypical lymphoid hyperplasia.

We have karyotyped cells from a lymph node of a patient with atypical lymphoid hyperplasia. Among other clonal chromosomal abnormalities, a t(2;19) translocation was observed with breakpoints at 2p11.2 and 19q13. The genes for transforming growth factor alpha and beta have been mapped to 2p11-p13 and 19q13, respectively, but Southern blot analysis did not reveal any alteration in the structure of these genes. Similarly, the kappa immunoglobulin gene, which maps to 2p11-p12 was not rearranged. In addition, Southern blot analysis using immunoglobulin and T-cell receptor genes as probes, did not demonstrate any clonality of either B or T cells. We propose that this patient represents an early, polyclonal stage of atypical hyperplasia. The chromosome changes observed may have been one of the etiologic factors causing this disorder.