Fine needle aspiration biopsy cytology of paragangliomas. Cytologic, light microscopic and ultrastructural studies of three cases

Paragangliomas are uncommon tumors arising in paraganglion tissue, which is especially well represented in the head and neck. In our hospital three head and neck masses recently proved to be paragangliomas on aspiratory biopsy cytology, with subsequent histologic confirmation. One was an apparently benign carotid body tumor, while the others were metastatic nasopharyngeal paragangliomas. The latter two tumors were clearly malignant, with roentgenographically proven pulmonary metastases in one and widespread lymph node involvement in the other. Histologically all were vascular tumors composed of large cells with abundant cytoplasm and pleomorphic, sometimes bizarre nuclei. These characteristic chief cells were clearly evident on cytology, with pleomorphic nuclei, prominent nucleoli, clumped chromatin and generally eosinophilic, finely granular or reticular cytoplasm. However, the distinction between benign and malignant tumors depended on the presence of mitoses or a tumor diathesis. Cytology seems to be able to provide a diagnosis of paraganglioma and, in these cases at least, an estimation of the biologic behavior.