Flow cytometric determination of nuclear DNA content in benign adrenal pheochromocytomas

Nuclear DNA content of paraffin-embedded tissue from 19 clinically benign adrenal pheochromocytomas and 18 control adrenal glands was analyzed using flow cytometry. All control adrenal glands and 6 pheochromocytomas were diploid. Four tumors were tetraploid. Nine were aneuploid with relative DNA indices in the near diploid range in 2, in the peritriploid range in 5, and in the near tetraploid range in 2. These results indicate that aneuploid DNA content is a frequent occurrence in benign adrenal pheochromocytomas. Aneuploidy per se is not a specific marker of malignancy in these tumors as has been suggested by previous reports.