Relation between DNA ploidy and the clinical behavior of phyllodes tumors.

We studied the DNA histograms obtained by flow cytometry from a series of six giant fibroadenomas and ten phyllodes tumors to determine if the analysis of DNA ploidy would help to predict clinical behavior. We were unable to document any relation between ploidy and histologic appearance, recurrence, metastasis, lesion size, or patient age. DNA aneuploid stem cell lines were seen in 75% of histologically benign phyllodes tumors, 50% of histologically malignant phyllodes tumors, and approximately 33% of giant fibroadenomas.