Acinar Atrophy, Fibrosis and Fatty Changes Are Significantly More Common than Sjogren's Syndrome in Minor Salivary Gland Biopsies.

Background and Objective: Hyposalivation and xerostomia can result from a variety of conditions. Diagnosis is based on a combination of medical history, clinical and serological parameters, imaging, and minor salivary gland biopsy when indicated. The Objective was to characterize microscopic changes in minor salivary gland biopsies taken in patients with xerostomia. Materials and Methods: 10-year retrospective analysis of minor salivary gland biopsies, 2007-2017. Histomorphometric analysis included gland architecture, fibrosis, fat replacement, inflammation and stains for IgG/IgG4, when relevant. Results:  64 consecutive biopsies, of which 54 had sufficient tissue for diagnosis of Sjogren's Syndrome (SS) were included (18 males, 46 females, average age 56 (±12.5) years). Only 12 (22.2%) were microscopically consistent with SS, none stained for IgG4. Medical conditions were recorded in 40 (63%), most frequently hypertension and hyperlipidemia (28% each). Medications were used by 45 (70%), of which in 50% more than one. Xerostomia in non-SS cases was supported by abnormal gland morphology, including acinar atrophy, fibrosis and fatty replacement. All morphological abnormalities are correlated with age, while fatty replacement correlated with abnormal lipid metabolism. Multiple medications correlated with microscopic features which did not correspond with SS. Conclusions: SS was confirmed in a minority of cases, while in the majority fatty replacement, fibrosis and multiple medications can explain xerostomia, and are related to aging and medical conditions. Medical history and auxiliary tests could lead to correct diagnosis in non-SS patients, avoiding biopsy. The necessity of a diagnostic biopsy should be given serious consideration only after all other diagnostic modalities have been employed.