INCIDENCE AND HISTOLOGY OF HUMAN ACCESSORY PAROTID-GLANDS

The parotid glands of 228 Japanese human cadavers were examined to determine the incidence and histological features of accessory parotid glands. The incidence was found to be 56% with no differences between right and left sides or between sexes. Thirty parotid glands and their associated accessory glands were examined histologically: eight of these accessory glands were found to be mixed secretory glands (i.e., containing both serous and mucous acini). Thus, the pattern of differentiation of a significant fraction of accessory glands differs from that of the am parotid gland: it appears that mixed acini, present in the early stages of development, persist into later life, and their presence may be related to tumors developing at these sites.