Neuroendocrine markers in paragangliomas of the head and neck

Eighteen paragangliomas of the head and neck (11 carotid body tumors, four glomus tympanicum tumors, three glomus jugulare tumors) were studied retrospectively. Tissue from each of these tumors was immunostained for the presence of serotonin, a variety of neuropeptide hormones, and the enzyme neuron-specific enolase (NSE). Seven tumors were studied by electron microscopy. The clinical and laboratory records were reviewed for evidence of endocrine activity or metabolic imbalance. All tumors displayed diffuse and intense immunostaining for NSE. In addition, a wide variety of hormonal substances could be identified. Those most frequently demonstrated were serotonin and leu-enkephalin. Ten of the 11 carotid body tumors demonstrated immunoreactivity for multiple hormones. By electron microscopy all tumors contained a heterogeneous population of membrane-bound neurosecretory granules. None of these tumors was associated with a clinically apparent endocrine syndrome. We conclude that paragangliomas of the head and neck are neuroendocrine tumors that are capable of synthesizing a variety of hormonal substances. These hormonal substances rarely elicit a clinically apparent endocrine or metabolic imbalance. All of the tumors demonstrated immunostaining for NSE. Future studies on serum levels of NSE may provide useful diagnostic and follow-up data.