AN IMPORTANT SUBGROUP OF PHYLLODES TUMORS OF THE BREAST IS CHARACTERIZED BY REARRANGEMENTS OF CHROMOSOMES 1Q AND 10Q

From a study of 10 cases of our own and 13 cases of the literature, an omalies of chromosome Iq and 10q emerge as consistently occurring chan ges in an important subgroup of phyllodes tumors of the breast. Anomal ies of chromosome were the most frequent ones, with a gain of Iq mater ial, and histologically the tumors in which these anomalies were found were low grade malignancies. Structural changes of 10q emerged as the second most frequent chromosome change.