We compared the immunoexpression of 5 myoepithelial cell (MEC) markers (alpha-smooth-muscle actin, calponin, h-caldesmon, vimentin, and S-100-protein) using 16 pleomorphic adenomas (PA), 15 adenoid cystic carcinomas (ACC), and 3 epithelial-myoepithelial carcinomas (EMC) of salivary glands. The alpha-smooth-muscle actin was useful for identification of MECs, especially in cribriform and tubular ACC, followed by EMC. Calponin was similar to alpha-smooth-muscle actin, except for polygonal and plasmacytoid cells of PA and for solid ACC, which showed alpha-smooth-muscle actin negative and calponin positive. H-caldesmon was negative. Vimentin immunostained all MEC types, and was negative in luminal cells. S-100 protein was expressed both in the nuclei and cytoplasm of MECs and luminal cells, especially in PA. The best way to identify MEC is using alpha-smooth-muscle actin or calponin, plus vimentin, since in tumors MECs are hardly ever fully differentiated.

Oral squamous cell carcinoma (OSCC) is the fifth most common type of cancer in the world. The effect of some etiological factors is well established in the literature, such as consumption of tobacco and alcohol. However, approximately 15 to 20% of all oral cancer cases occur in patients without the traditional risk factors, reflecting in numerous cases of OSCC in non-smokers and non-alcoholic drinkers. Also, several studies have suggested a possible association between human papillomavirus and OSCC. Under these aspects, the purpose of this study is to address cases of oral cancer in non-smokers and non-drinkers focusing on the role of HPV, thus contributing to improve the diagnosis and monitoring of OSCC. A computer database search was performed using the Pubmed database. The search key words were: epidemiology, oral squamous cell carcinoma, risk factors and human papillomavirus. It is important to assess patients without the potential risk factors, since this knowledge may help identifying other features associated with the occurrence of oral cancer, enabling an appropriate clinical management and monitoring.

To investigate whether salivary carcinomas with and without myoepithelial differentiation could present differences regarding degree of angiogenesis, we compared tumor vascularization between adenoid cystic (31 cases) and epithelial-myoepithelial carcinomas (14) versus mucoepidermoid (37) carcinoma. The expression of peroxiredoxin I was also studied to verify the potential relationship between cellular metabolism and microvascular density. Microvascular density for CD34 and CD105 were significantly lower in carcinomas with myoepithelial differentiation. However, no correlation was found between degree of angiogenesis and amounts of myoepithelial cells. High-grade peroxiredoxin I expression was found in 73.7% of mucoepidermoid carcinomas, whereas 85.1% of carcinomas with myoepithelial differentiation presented low-grade expression. In conclusion, carcinomas with myoepithelial differentiation, regardless of the amounts of myoepithelial cells, are associated to a significantly lower vascular density. The reasons for this lower angiogenic activity remain to be determined but could be related to metabolic characteristics of the cancer cells.

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This study evaluated the expression of E-cadherin and beta-catenin in salivary gland tumors. Twelve biopsy specimens from cases diagnosed as pleomorphic adenoma, 17 adenoid cystic carcinomas, 10 epithelial-myoepithelial carcinomas, and 4 polymorphous low-grade adenocarcinomas were immunohistochemically labeled for E-cadherin and beta-catenin antibodies. Healthy salivary glands were used as controls. Membrane-associated E-cadherin and beta-catenin expression was present in all the tumor types studied. E-cadherin and beta-catenin showed a similar distribution; however, beta-catenin labeling was weaker than that for E-cadherin. In the epithelial-myoepithelial carcinomas, myoepithelial cells exhibited diffuse nuclear staining, although occasional cells presented only focal labeling. Epithelial-myoepithelial carcinomas present changes in [.beta]-catenin expression but the other salivary tumors studied do not, which may reflect divergence in tumorigenesis of this extensive subset of salivary gland tumors.

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The authors examined the clinical and histopathological features of 48 cases of mucocele of the glands of Blandin-Nuhn. Data of all patients with mucocele treated at the Department of Oral and Maxillofacial Surgery totaled 312 cases during the 6-year period of study were analyzed. There was no sex predominance, and most patients were younger than 20 years. All lesions were located on the ventral surface of the tongue, and they were more frequently observed at the tip of the tongue whereas few ones occurred more posteriorly. All lesions presented a polypoid appearance. Histopathologically, the mucoceles were of the extravasation type and trauma might be the most frequent etiological factor. This type of mucocele was the second most frequent one and should not be considered rare.