DNA ANALYSIS OF ATRIAL MYXOMAS

The atrial myxoma is a primary tumor of the heart which may have an uncertain clinical course. In this study, we performed flow cytometric DNA analysis of 15 paraffin-embedded atrial myxomas and correlated DNA ploidy status and proliferative fraction with clinical findings. Twelve of 15 cases (80 percent) were diploid and the remaining three cases (20 percent) were aneuploid. Two patients with aneuploid histograms were free of tumor at the time of follow-up; the third patient experienced local tumor recurrence and metastases. Five patients with diploid myxomas demonstrated an elevated (greater-than-or-equal-to 17 percent) proliferative cell cycle fraction; four of these patients experienced embolic phenomenon or tumor recurrence. This pilot study suggests that an atrial myxoma with either aneuploid DNA content or elevated proliferative fraction may be associated with aggressive biologic behavior.