Concurrent
DNA ploidy by flow cytometry and interphase FISH analysis of chromosomes 6 through 12, 17, 18, X, and Y were prospectively performed on 22
salivary gland neoplasms (four benign and 18 malignant) to investigate the diagnostic and
biological implications of their alterations in these
neoplasms. Our results show that
benign neoplasms lack
DNA aneuploidy and numerical
chromosomal abnormalities. Low-grade
malignant neoplasms, except for two lesions, manifested small chromosomal gains and losses and were generally
DNA diploid or near-diploid
aneuploid, whereas all high-grade
tumors showed marked polysomy and were
DNA aneuploid. Marked intratumoral and intertumoral chromosomal heterogeneity also were noted in and between individual
tumors. Although polysomy was the main finding in
DNA aneuploid lesions,
monosomy was more noted in
DNA diploid
neoplasms and was restricted to chromosomes 8, 11, and 17. Significant correlation between the
DNA index, chromosomal aneusomy, histological grade, and
tumor stage was noted. Our study indicates that (1) benign
salivary gland neoplasms lack gross
DNA content and numerical
chromosomal abnormalities, (2) clonal chromosomal alterations are manifested in most
DNA diploid and all
DNA aneuploid malignant
tumors, (3) chromosomal gain is the most common alteration; chromosomal loss is less frequent and restricted to certain chromosomes, and (4)
DNA aneuploidy and chromosomal aneusomy characterize
tumors with aggressive features.