del(6q) as a possible primary change in malignant mesothelioma

Detailed cytogenetic and fluorescence in situ hybridization analysis of an untreated pleural malignant mesothelioma revealed two clonal cell populations, both with a single abnormality affecting chromosome 6. The majority of cells had a deletion together with an inversion of the long arm of chromosome 6, while a smaller population showed loss of this chromosome. The normal 6 was retained. Most reports show that mesotheliomas are characterized by complex karyotypes, involving numerous chromosomes. Abnormalities of chromosome 6 (particularly deletions of the long arm) are among the consistent changes. Our case apparently is the first report of a mesothelioma with a single change involving chromosome 6, which could be the primary cytogenetic change.