OBSERVATIONS BY CHROMOSOME-BANDING, FISH AND IMMUNOHISTOCHEMISTRY IN AN ADENOID CYSTIC CARCINOMA WITH DEL(17)(P13) AS THE SOLE DEVIATION

We report on an adenoid cystic carcinoma (ACC) with a clonal deletion of 17p as the only karyotypic abnormality. Using different chromosome 17-derived probes we showed by FISH that the deletion encompassed the p53 tumour suppressor gene. Immunohistochemical analysis revealed over expression of p53 protein in a subpopulation of cells, suggesting a mu tation in the remaining p53 allele in these cells. Our findings provid e novel information about possible progressional pathways in ACC, and demonstrate the value of combining conventional cytogenetic analysis w ith molecular cytogenetic and immunohistochemical methods. This approa ch is particularly useful in cases with minor cytogenetic abnormalitie s at the border of visibility.