Comparison of chromosome analysis to DNA content by flow cytometry for pediatric tumors

Chromosome analyses in a series of 50 pediatric tumor samples showed abnormal chromosome number, ranging from hypodiploid to tetraploid. Aliquots of the same solid tumor samples were analyzed by flow cytometry (FCM). Material from spontaneous abortions and 12 tumor samples with normal chromosomes were also compared in a control series of 83 samples. Tumors or abortuses with 44-48 chromosomes could not be differentiated from material with normal diploid complement by FCM. However, greater than or equal to 3-4 extra chromosomes produced detectable differences in mean DNA index. Triploidy and tetraploidy were readily identified by FCM. It is concluded that FCM could identify an important group of hyperdiploid pediatric tumors, as well as 3N and 4N tumor complements.