A high frequency of tumors with rearrangements of genes of the HMGI(Y) family in a series of 191 pulmonary chondroid hamartomas

Pulmonary chondroid hamartomas (PCHs) are benign mesenchymal tumors that of ten are characterized by specific chromosomal aberrations. Herein we report our cytogenetic and molecular cytogenetic (FISH) studies on 191 PCHs, incl uding 48 previously published cases. In this series, 134/191 PCHs (70.2%) s howed either abnormalities of chromosomal bands 6p21 (21 tumors), 12q14-15 (95 tumors), or had other abnormalities (18 tumors). Two tumors had a 6p21 aberration together with a 12q14-15 aberration. The most frequent transloca tions were t(12;14)(q15;q24) (19 cases) and t(6;14)(p21.3;q24) (18 cases), both in either simple or complex form. By FISH with cosmids spanning the ge ne encoding the high-mobility-group protein HMGIC, we were able to show a r earrangement within or close to HMGIC in all tumors with 12q14-15 abnormali ties tested, in 11 tumors with an apparently normal karyotype, and in 4 tum ors with compiler abnormalities without cytogenetically visible alterations of chromosomes 12. Rearrangements of HMGIY or its immediate surroundings w ere shown for 21 cases with 6p21 aberrations and three cases with other chr omosomal abnormalities but without cytogenetically visible alterations of c hromosomes 6. Genes Chromosomes Cancer 26:125-133, 1999. (C) 1999 Wiley-Lis s.