Karyotypic evolution in a human mucoepidermoid carcinoma

Chromosomes were studied in cultured material from two different areas of a human mucoepidermoid carcinoma. The detailed banding analyses showed no less than 41 different karyotypes. Comparisons between these revealed (1) that the tumour probably had originated with a normal, diploid stemline; (2) that the progression had mainly proceeded by steps in a hyperdiploid direction, by, as a rule, sequential numerical deviations; and (3) that there existed at least eight further, different, evolutionary products from the original stemline. The complex progressional pattern disclosed in the present case contrasts with cytogenetical data documented for most human benign as well as malignant tumour types.