Combined strategy of conventional cytogenetics, fluorescent in situ hybridization and chromosome morphometry for analysis of parotid gland tumor

The limiting factors in conventional cytogenetic analysis of cell culture, especially of solid tumors, include insufficient metaphases, overgrowth of abnormal mitotic cells by normal cells, and suboptimal quality of harvesting and banding. Despite the availability of numerous protocols to induce G-banding, as well as Q-, R-, and C-banding, occasions still arise in which the analysis is severely limited by these factors and incomplete conclusions are often drawn as to the precise nature of the chromosomal abnormality, if indeed any can be detected. By adopting a rational approach of (1) close monitoring of cultures and rapid harvesting as soon as it is feasible, and (2) analysis of available metaphases by a combination of the GTG technique, fluorescent in situ hybridization (FISH), and chromosome morphometry using a graphic arts tool, a significant improvement in success rate may be more readily achieved. Here pathological and cytogenetic data are presented of a case of parotid gland carcinoma ex mixed tumor with the karyotype of 46, XX, del(5)(q12), dir ins(8;5)(q12;q12qter), add(12)(p13)/46, XX. This case is utilized to illustrate the importance of application of our combined strategy.