Neuroendocrine carcinoma of the parotid gland: a report of two cases with ultrastructural and immunohistochemical studies.

Two cases of primary small cell carcinoma of the parotid gland are reported. This rare neoplasm usually presents as a painful or painless mass in the gland. The finding of neurosecretory granules by electron microscopic study, combined with strong immunoreactivity for neuron-specific enolase and chromogranin, confirms the true neuroendocrine origin of the carcinoma. This tumor appears to have a better prognosis than small cell carcinoma of the lung, which it resembles histologically.