Fine needle aspiration cytology of paraganglionic tumors.

A comparative study of six paragangliomas from different locations and with different clinical behavior was performed. The fine needle aspirates in all cases were similar: abundant cells with round or oval nuclei and marked anisokaryosis with a tendency to form acini or follicular structures. Pheochromocytomas often contained binucleated cells and had cells with prominent intranuclear cytoplasmic inclusions more often than did other paraganglionic tumors. Similar features were seen in the excised tumors. Evaluation of the significance of nuclear variations with morphometry confirmed the subjective impression that nuclear pleomorphism is not an indicator of the biologic behavior of these lesions; paradoxically, malignant paragangliomas show less anisokaryosis than do their benign counterparts.