Bilateral familial carotid body paragangliomas. Report of a case with DNA flow cytometric and cytogenetic analyses. A case study of bilateral familial carotid body paragangliomas with DNA flow cytometric and cytogenetic analyses is presented. Analysis of tumor cell nuclear DNA content by flow cytometry revealed aneuploid cell populations in both tumors. Standard cytogenetic analysis (Giemsa-banding technique used) of the right carotid body paraganglioma showed no evidence of numerical or structural abnormalities. We describe parameters currently used to "predict" biological behavior in these tumors. 