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 often are characterized by specific chromosomal aberrations. Herein we report our cytogenetic and molecular cytogenetic (FISH) studies on 191 PCHs, including 48 previously published cases. In this series, 134/191 PCHs (70.2%) showed 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 translocations 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 gene encoding the high-mobility-group protein HMGIC, we were able to show a rearrangement within or close to HMGIC in all tumors with 12q14-15 abnormalities tested, in 11 tumors with an apparently normal karyotype, and in 4 tumors with compiler abnormalities without cytogenetically visible alterations of chromosomes 12. Rearrangements of HMGIY or its immediate surroundings were shown for 21 cases with 6p21 aberrations and three cases with other chromosomal abnormalities but without cytogenetically visible alterations of chromosomes 6. Genes Chromosomes Cancer 26:125-133, 1999. (C) 1999 Wiley-Liss.