Image analysis of fatty infiltration in labial salivary gland biopsies: extent and its correlation to age, obesity and diabetes.

Background: Fatty infiltration of minor salivary gland parenchyma is relatively frequent, but not extensively examined histopathological phenomenon in biopsy samples. Its extent and relation to several suspected background diseases are not well understood.

Methods: In this study, we examined the presence and extent of fatty infiltration on digitally scanned versions of the periodic acid/Schiff-stained minor salivary gland slides of 275 patients. As a result of the image analysis, fatty infiltration was expressed in per cent of the whole selected area. The presence and extent of this change were compared to age, diabetes mellitus and body mass index in various statistical analyses.

Results: Significantly higher age and body mass index values were found in the fatty infiltration positive than in the negative group. We also found that not only the number of fatty infiltration positive cases was increased significantly in the gradually worsened body mass index groups, but the extent of fatty infiltration also increased as the obesity worsened. Age also showed significant correlation with the extent of fatty infiltration.

Discussion: All of these findings support that the age (which seemed the only independent variable) shows strong correlation with the presence of the fatty infiltration but obesity may also play important role in the development and the extent of this change. Because of its frequency in elderly, at least partly, the fatty infiltration might be responsible for the xerostomia. We also think that presence of fatty infiltration should be mentioned in the histopathological report of salivary gland biopsies.