Chronic sialadenitis of the submandibular gland (so-called Küttner tumor)

Two cases of chronic sialadenitis of the submandibular gland (so-called Küttner tumor) are reported. Clinically, they are asymptomatic except for firm swellings which are similar to neoplasms. Light microscopic observations revealed that the lesion is characterized by various degrees of atrophy and/or destruction of acini, infiltration of inflammatory cells, periductal fibrosis and lymph follicle formation. With the electron microscope, a marked increase of collagen fibers are observed throughout the gland parenchyma, and the secretory granules of acinal cells in the remaining acini remarkably decreased in number. We suggest that an autoimmune mechanism may play a role in case 1 and that an ascending infection through the duct system may be a main factor in case 2.