Chronic sclerosing unspecific sialadenitis or Küttner tumor, is an infrequent inflammatory lesion of submandibular gland. We report a 60 years old male presenting with a slowly growing, painless, bilateral submandibular tumor of two years of evolution. Pathological examinations showed marked atrophy of glandular parenchyma with increased fibrous connective tissue and an intense lymphocytic infiltration with lymphoid follicle formation. Lymphocyte population study with kappa, lambda, CD20 and CD45RO antibodies was similar to that observed in reactive lymph nodes. There was no over expression of Bcl-2 gene protein, involved in the phenomenon of apoptosis of glandular tissue, that could explain the pathogenesis of atrophy. This protein was positive only in lymphoid cells and glandular conducts. An immune etiology, with replacement of glandular tissue by lymphoid and fibrous connective tissue is suggested.