Ultrastructural study of glycogen-rich oxyphilic adenoma of the nasopharyngeal minor salivary gland.

A glycogen-rich adenoma occurring in the minor salivary gland of the nasopharynx in a 41-year-old woman was studied ultrastructurally. The cytoplasm of the tumour cells was abundantly filled with glycogen particles. The tumour cells possessed many mitochondria, a great number of microvillous processes and microvilli and were joined to each other by desmosomes. These findings suggest that this adenoma is of salivary duct epithelial origin most probably from storing striated ductal cells, and is a variant of monomorphic oxyphilic adenoma.