Radioprotective Effect of Vitamin E in Parotid Glands: a Morphometric Analysis in Rats

The aim of this study was to evaluate the radioprotective effect of vitamin E on rat parotid glands by morphometric analysis. Sixty male rats were divided into 5 groups (n=6): control, in which animals received olive oil solution; olive oil/irradiated, in which animals received olive oil and were irradiated with a dose of 15 Gy of gamma radiation; irradiated, in which animals were irradiated with a dose of 15 Gy gamma radiation; vitamin E, which received α-tocopherol acetate solution; vitamin E/irradiated, which received α-tocopherol acetate solution before irradiation with a dose of 15 Gy gamma rays. Half of the animals were euthanized at 8 h, and the remaining at 30 days after irradiation. Both parotid glands were surgically removed and morphometric analysis of acinar cells was performed. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Morphometric analysis showed a significant reduction in the number of parotid acinar cells at 30 days in olive oil/irradiated and irradiated groups. In groups evaluated over time a significant reduction was shown at 30 days in olive oil/irradiated and irradiated groups, indicating that ionizing radiation caused tissue damage. The vitamin E/irradiated group presented more acinar cells than the irradiated group, but no statistically significant difference was observed (p>0.05). In conclusion, vitamin E seems to have failed as a radioprotective agent on acinar cells in rat parotid glands.

O objetivo neste estudo foi avaliar o efeito radioprotetor da vitamina E sobre glândulas parótidas de ratos por meio de análise morfométrica. Sessenta ratos machos foram divididos em cinco grupos: controle, no qual os animais receberam solução de óleo de oliva; óleo de oliva irradiado, em que os animais receberam óleo de oliva e foram irradiados com uma dose de 15 Gy de radiação gama; irradiado, em que os animais foram irradiados com uma dose de 15 Gy de radiação gama; vitamina E, no qual receberam solução de acetato α-tocoferol; vitamina E irradiado, os quais receberam solução de acetato de α-tocoferol antes da irradiação com uma dose de 15 Gy de radiação gama. Metade dos animais foi eutanasiada em 8 h, e o restante aos 30 dias após a irradiação. Ambas as glândulas parótidas foram removidas cirurgicamente e análise morfométrica das células acinares foi realizada. Os dados foram submetidos à Análise de Variância com 2 fatores e teste de Tukey (α=0,05). A análise morfométrica mostrou uma redução significativa no número de células acinares da glândula parótida aos 30 dias nos grupos óleo irradiado e irradiado. Nos grupos avaliados ao longo do tempo uma redução significativa foi mostrada aos 30 dias nos grupos óleo irradiado e irradiado, indicando que a radiação ionizante causou danos teciduais. O grupo vitamina E/irradiado apresentou mais células acinares que o grupo irradiado, mas diferença estatisticamente significante não foi observada. Em conclusão, a vitamina E parece ter fracassado como um agente radioprotetor nas células acinares das glândulas parótidas de ratos.

Rhinosporidiosis of the parotid duct presenting as a parotid duct cyst - A report of three cases.

Rhinosporidiosis is a chronic granulomatous infection caused by Rhinosporidium seeberi. Rhinosporidiosis has been reported from many countries but is endemic in certain parts of India and Sri Lanka. The common sites of involvement are the nose and nasopharynx followed by ocular tissue. Rhinosporidiosis is also known to involve many rare sites and may become disseminated to occur in a generalized form. Rhinosporidiosis of the parotid duct is rare and only five reported cases could be found in the literature. We report three cases of rhinosporidiosis of parotid duct presenting clinically as a parotid duct cyst. Rhinosporidiosis was diagnosed by histopathology. None of these patients had rhinosporidiosis at any other site

Benign hyperplasia of duct-associated lymphoid tissue: Report of a case and review of literature.

Focal lymphoid tissue is ubiquitously present in the oral mucosa and serves as a barrier for entrapment of antigens. The mucosa-associated lymphoid tissue is generally dispersed and sometimes associated with the ducts of the minor salivary glands. Proliferation of the duct-associated lymphoid tissue (DALT) is rarely reported, though probably of common occurrence. We report a case of benign hyperplasia of DALT in the buccal mucosa of a 58-year-old male. The histogenesis and pathological implications of this tissue are discussed and the need for recognition of this entity is stressed.

Rhinosporidiosis of parotid duct.

Rhinosporidiosis is a benign chronic granulomatous infection caused by Rhinosporidium seeberi. Rhinosporidiosis is endemic in south Asia, notably in southern India and Sri Lanka. Majority of the cases have been reported to occur in upper respiratory sites, notably anterior nares, nasal cavity, nasopharynx, larynx and soft palate. Only two rare cases of involvement of parotid duct, have been reported in literature. Hence, this case will probably be the third to be reported.

Salivary duct carcinoma of the parotid gland: the cytohistological features.

A 62-year-old man presented with rapidly growing tumour in the right parotid region with associated pain and facial nerve palsy. Based on the fine needle aspiration cytology report of high-grade mucoepidermoid carcinoma, parotidectomy was performed which showed features of salivary duct carcinoma. The smears were reviewed to identify the potential pitfalls in the cytological diagnosis of salivary duct carcinoma.

Kimura disease with proliferative squamous metaplasia: an unusual finding and a potential diagnostic pitfall.

Kimura disease is a rare form of chronic inflammatory disorder involving subcutaneous tissue, predominantly in the head and neck region and frequently associated with regional lymphadenopathy and/or salivary gland involvement. We present a case of Kimura disease in a 28-year-old male which showed florid squamous metaplasia in the salivary gland ducts and salivary duct inclusions in the intraparotid nodes besides the usual features of Kimura disease. The squamous metaplasia was extensive enough to pose a diagnostic dilemma. We describe this case to highlight the rare histological finding of florid squamous metaplasia in Kimura disease and its diagnostic implications.

Salivary duct carcinoma of the palate.

Salivary duct carcinoma is a rare high-grade neoplasm that more frequently affects the parotid gland. Though neoplasms of this type are infrequent in minor salivary glands, they are less aggressive and may lead to early diagnosis before distant metastases could occur. Salivary duct carcinoma is also the most frequent epithelial component of carcinosarcoma. The present article reports a case of SDC of the palate in a 26-year-old male and discusses SDC as a malignant epithelial component in carcinosarcoma.