Oncocytic hyperplasia in the human minor salivary glands: a post-mortem study

The Potential of Light Microscopic Features of the Oral Mucosa in Predicting Post-mortem Interval

Objectives

The post-mortem interval (PMI) refers to the amount of time elapsed between death and discovery of the body. This study aimed to evaluate light microscopic cellular changes in the oral mucosa and identify the potential of this method for predicting PMI.

Methods

This prospective study was conducted between July 2016 and January 2018 at the Institute of Dental Sciences, Siksha ‘O’ Anusandhan University, Bhubaneswar, India. A total of 150 post-mortem (including 75 gingival and 75 buccal mucosa samples) and 40 ante-mortem (including 20 gingival and 20 buccal mucosa samples) tissue samples were compared using haematoxylin and eosin, periodic acid-Schiff (PAS) and van Gieson stains. Microscopic changes in the epithelium and connective tissue were categorised according to PMI stage as early (<12.5 hours since death), intermediate (12.5–20.5 hours since death) or late (>20.5 hours since death).

Results

Most epithelial cellular changes occurred early, except for arc-shaped nuclei and epithelial shredding which were intermediate and late changes, respectively. However, microscopic changes in the connective tissue were only observable at ≥12.5 hours. There was a progressive decrease in intensity in van Gieson stains and an increase in intensity in PAS stains as PMI increased. Several microscopic features were found to be significant predictors of PMI including epithelial homogenisation, cytoplasmic vacuolation, nuclear degeneration, arc-shaped nuclei, chromatin clumping, red blood cell clumping and lysis, melanin incontinency, myofibril degeneration, salivary gland acini degeneration and epithelial connective tissue separation (P <0.050 each).

Conclusion

These findings indicate that microscopic evaluation of the oral mucosa may be helpful for PMI prediction.

Island of salivary gland in adipose tissue: a report of three cases

Although uncommon, many variants of lipomatous lesions in or around salivary glands have been reported in the literature. We report a series of three such cases in the minor salivary gland region. The first case (oral floor) is a well-circumscribed lipocytic lesion admixed with glandular components (mucous acini, serous demilunes and ducts). The second case (alveolar mucosa) is a diffuse lipomatous proliferation with entrapped salivary glandular elements, muscles and blood vessels. The third case (palate) is similar to the first case but the gland is located at the periphery of the lesion. The purpose of the article was to report these three lesions and discuss in relation to other pertaining lipomatous lesions (sialolipoma, lipoadenoma, lipomatosis, lipometaplasia in pleomorphic adenoma and infiltrating lipoma).

[Focal oncocytosis of the salivary glands and etiopathogenetic relations]

Focal oncocytosis in minor and major salivary glands is a relatively rare condition. We found it in 92 (8.7%) of 1056 biopsy and operation specimens of the salivary glands. There was a nearly balanced sex ratio. Oncocytosis was found mainly in patients between the 5th and 8th decades of life, with a progressive tendency. Oncocytic transformations of the ductal epithelium were always associated with additional lesions. These were chronic sialadenitis, hyperplasia and metaplasia of ductal epithelium and morphological signs of central or peripheral salivary obstruction. As etiologic factors or fundamental diseases, mainly neoplasms and chronic inflammations with hyperplasia of the oral mucosa and a primary chronic (obstructive) sialadenitis were found, but age-related mechanisms could not be excluded. We believe the oncocytic transformation to be a regressive alteration of previously hypertrophic or hyperplastic ductal epithelium with the appearance of a mitochondriopathy.