Does conventional cytogenetics detect the real frequency of 19q13 aberrations in benign thyroid lesions? A survey of 38 cases.

Structural aberrations involving chromosomal band 19q13.4 are examples of clonal cytogenetic deviations that have been detected in subgroups of follicular thyroid adenomas and goiters. About 45% of the adenomas and 8% of the goiters showed clonal aberrations, about 20% of which involve 19q13. The aberrations are translocations with a remarkable variation of the translocation partners of chromosome 19. Considering that structural changes involving small chromosome segments do not always have a characteristic band to be accurately identified, one may assume an even higher rate of these aberrations in thyroid lesions. To detect hidden 19q13 translocations, we performed fluorescence in situ hybridization analyses with a subtelomeric 19q specific probe on a subset of 38 thyroid adenomas with an apparently normal karyotype. No hidden chromosome abnormality was detected in our study, indicating that conventional cytogenetics reflects the true percentage of 19q13 aberrations in follicular thyroid adenomas.