Clonal Rearrangement of Chromosome Band 6p21 in the Mesenchymal Component of Pulmonary Chondroid Hamartoma1

Pulmonary chondroid hamartomas (PCH) are biphasic benign tu mors that contain both mesenchymal and epithelial populations. In this report we describe two PCH in which clonal translocations at chromo some band 6p21 were demonstrated in mesenchymal cells. One of these had a unique translocation, t(6;14Xp21;q24), that was also found in one of two PCH karyotyped previously. The t(6;14) has not been described in other varieties of benign or malignant neoplasia. The 6p21 aberra tions are of particular interest because break points in this chromosomal region appear to be characteristic of endometrial polyps. Endometrial polyps, like PCH, are biphasic benign tumors in which mesenchymal clonality has been demonstrated.