[The accessory salivary glands in Sjögren's syndrome. Histological and ultrastructural study. Correlations with sialographic changes in the principal glands].

139 salivary gland biopsies have been studied in patients with Sjögren's syndrome. Histologically, we classified labial salivary gland injuries (127 cases) in 3 groups based on striated duct distension: first, some tubular ectasia with few interstitial lymphoid cells; second, much ectasia associated with many lymphoid cells and early pericanalar sclerosis; third, intensive ectasia, scarce lymphocytes, severe peri and intralobular sclerosis and extensive destruction of acini. This grading is positively correlated with that of parotid biopsies and also with abnormalies on 60 parotid sialographic radiogramms performed simultaneously. Histoenzymological and ultrastructural studies demonstrate, at an early stage of the disease, epithelial and myoepithelial alterations in striated ducts, with tubular ectasia. Simultaneously, an intensive regeneration from intercalated ducts takes place. Nevertheless that regeneration fails to repair myoepithelial cells. Furthermore, young myoid cells, leaving tubular walls, migrate in interstitial tissue and are responsible for accumulation of membranoid material and later of collagen sclerosis.