Duct-like structures in odontogenic epithelium of compound odontoma

During a histologic investigation of compound odontomas, numerous duct-like structures scattered in odontogenic epithelia were found in 3 of 7 cases. The duct-like lumina were 10 to 150 microns in diameter, and lined with eosinophilic, and relatively regular-arranged epithelial cells which were cuboidal or flat in shape and which had a hyperchromatic nucleus, resulting in some resemblance to the small duct of excretory glands. Amorphous material stained palely with hematoxylin was present within the duct-like lumina, but showed somewhat weaker reaction to mucous stainings. Mucous secreting cells could not be found in any odontogenic epithelia. Although no firm conclusion of histogenesis and pathologic significance of the duct-like structure in odontogenic epithelium, the result of the present examination suggests that the odontogenic epithelial cells may have an ability to form duct-like structure under the unknown condition.