Defining objective morphometric thresholds for the diagnosis of adenomatoid hyperplasia of minor salivary glands

Adenomatoid hyperplasia (AH) of minor salivary glands is a benign lesion that clinically mimics salivary gland neoplasms. Histopathologic diagnosis currently relies primarily on qualitative assessment, as objective quantitative criteria and baseline morphometric reference values for normal minor salivary glands have not been formally established. This study aimed to explore objective histomorphometric parameters for the diagnosis of AH and to characterize quantitative reference ranges for normal minor salivary glands.

A retrospective controlled clinico-pathologic study was conducted including 35 AH cases and 35 normal minor salivary gland controls. Digital measurements of long- and short-axis diameters of large and small acini were obtained using ImageJ software, and relative surface area involvement was calculated.

The mean long-axis diameter of large acini (LAD-L) was significantly greater in AH than in controls (133.0 ± 21.5 µm vs. 66.6 ± 11.7 µm; p < .001). A cutoff value of 87.6 µm for mean LAD-L achieved complete differentiation between AH and normal glands within the present cohort (AUC = 1.00; 95% CI: 1.00-1.00). Enlarged acini occupied a mean of 71.9% of specimen surface area in AH. Within this single-center biopsy-based cohort, AH accounted for 33.3% of nonulcerated palatal masses, representing one of the more frequent diagnostic entities relative to other lesions.

Within this single-center biopsy-based cohort of nonulcerated palatal masses, AH represented a relatively frequent diagnosis. The proposed morphometric parameters may provide objective diagnostic support while also establishing quantitative reference values for normal minor salivary glands.