Mucoepidermoid carcinoma of the posterior-lateral border of tongue: a rare presentation.

Mucoepidermoid carcinoma (MEC) is the most common malignant tumour of the major and minor salivary glands. Minor salivary glands are scattered in different areas of the oral cavity such as palate, retromolar area, floor of the mouth, buccal mucosa, lips and tongue, but so far, only a few lingual MEC cases have been documented in the literature and most of the studies have shown a predilection for base and dorsum of the tongue. We report a rare case of MEC involving the posterior-lateral border of the tongue.

Baicalin induces human mucoepidermoid carcinoma Mc3 cells apoptosis in vitro and in vivo.

Mucoepidermoid carcinoma (MEC) is the most common malignant tumor in salivary glands and high-grade MEC in particular demonstrates little response to chemotherapy which has been used largely for palliative treatment of metastatic disease. Baicalin, one of the main active compounds of Scutellaria baicalensis, possesses anti-inflammatory, antioxidant and antitumor properties. In the present study, we investigated the growth inhibiting and apoptosis-inducing effects of baicalin on a highly metastatic human mucoepidermoid carcinoma cell line Mc3 for the first time. Baicalin exerted dose- and time-dependent antiproliferative potential against Mc3 cells as assessed by MTT assay. Baicalin treatment of Mc3 cells resulted in an accumulation of cells at the G0/G1 and G2/M phase with a concomitant decrease in cells processing to S phase as assessed by flow cytometry. Furthermore, baicalin induced apoptosis of Mc3 cells as determined by annexin V binding and PI dual staining, DNA fragmentation, nuclear condensation and in vivo tumor inhabitation. Rhodamine 123 assay indicated that baicalin caused cytotoxicity and induced apoptosis through decreasing the mitochondrial membrane potential in Mc3 cells. Our results suggest that baicalin seems to be very attractive as a new anticancer drug and a potential chemotherapeutic agent against human high-grade mucoepidermoid carcinoma.

Correlation between mucoepidermoid carcinoma grade and AgNOR count.

Mucoepidermoid carcinoma (MEC) is a malignant glandular epithelial neoplasm having an unpredictable behavior and a tendency to recur. Numerous parameters have been assessed to predict the outcome of this lesion, but have been deemed inadequate, with the exception of tumor stage and grade. In the present study, we attempted to correlate the proliferative activity of MEC with its histopathological grade, using argyrophillic nuclear organizer region (AgNOR) count. Thirty cases of MEC were included in the study. All the slides were stained using hematoxylin and eosin and silver nitrate techniques. Counting was performed at a magnification of x1,000 with an oil-immersion lens. Positive correlations were seen between AgNOR count and MEC grade (P < 0.05), with AgNOR count increasing in proportion with tumor grade. The AgNOR count in various grades of MEC indicates a relative progression in the proliferative activity of this tumor. This index is positively correlated with tumor grade, although there are some exceptions. The utility of AgNOR count in predicting the prognosis of MEC can be considered of importance; however, further assessment, such as survival studies, is necessary.

[Mucoepidermoid carcinoma of the thyroid: a case report and literature review]. / Carcinoma mucoepidermóide de tireóide: relato de caso e revisão da literatura.

The mucoepidermoid carcinoma is a neoplasia that usually occurs at salivary glands, breast, pancreas and gastrointestinal tract. The primary occurrence on thyroid gland is rare and only 33 cases were previously published. Although the majority of cases of mucoepidermoid carcinoma of the thyroid (MECT) show a benign evolution, this paper describes a patient with an aggressive tumor. A literature review over clinical, histopathological, immunohistochemical features and histogenetic origin was discussed.

Carcinoma mucoepidermóide de tireóide: relato de caso e revisão da literatura / Mucoepidermoid carcinoma of the thyroid: a case report and literature review / Mucoepidermoid carcinoma of the thyroid: a case report and literature review

O carcinoma mucoepidermóide é um tipo de neoplasia encontrada geralmente nas glândulas salivares, mamas, pâncreas e trato digestivo. O acometimento primário da glândula tireóide é muito raro, apenas 33 casos na literatura. Embora a maioria dos casos de carcinoma mucoepidermóide de tireóide (CMET) tenha evolução favorável, o caso clínico relatado descreve uma paciente com tumor agressivo e, a partir deste relato, é apresentada revisão da literatura quanto aos aspectos clínico, histopatológico, imunohistoquímico e origem histogenética dessa neoplasia.

The mucoepidermoid carcinoma is a neoplasia that usually occurs at salivary glands, breast, pancreas and gastrointestinal tract. The primary occurrence on thyroid gland is rare and only 33 cases were previously published. Although the majority of cases of mucoepidermoid carcinoma of the thyroid (MECT) show a benign evolution, this paper describes a patient with an aggressive tumor. A literature review over clinical, histopathological, imunohistochemical features and histogenetic origin was discussed.

In vivo and in vitro effects of macrolide antibiotics on mucus secretion in airway epithelial cells.

To examine the in vivo effects of macrolide antibiotics on mucus hypersecretion, we induced hypertrophic and metaplastic changes of goblet cells in rat nasal epithelium by intranasal instillation of ovalbumin (OVA) in OVA-sensitized rats and by intranasal LPS instillation. Oral administration of clarithromycin (CAM) (5-10 mg/kg) significantly inhibited OVA- and LPS-induced mucus production and neutrophil infiltration, whereas josamycin and ampicillin showed no effect. In vitro effects of macrolide antibiotics on airway epithelial cells were examined using NCI-H292 cells and human nasal epithelial cells cultured in air-liquid interface. Mucus secretion was evaluated by ELISA using anti-mucin monoclonal antibodies (anti-MUC5AC and HCS18). CAM and erythromycin significantly inhibited spontaneous and tumor necrosis factor-alpha (20 ng/ml)-induced mucus secretion from NCI-H292 cells at 10-6 to 10-7 M and from human nasal epithelial cells at 10-4 to 10-5 M. MUC5AC messenger RNA expression was also significantly inhibited. These results indicate that the 14-member macrolide antibiotics, CAM and erythromycin, exert direct inhibitory effects on mucus secretion from airway epithelial cells and that they may be useful for the treatment of mucus hypersecretion caused by allergic inflammation and LPS stimulation.

Intranuclear inclusions in fine needle aspirates of bronchial low grade mucoepidermoid carcinoma with clear cell change: a report of two cases.

BACKGROUND: Mucoepidermoid carcinoma of the bronchus is a rare neoplasm that can be recognized on histology as well as cytology by the presence of three characteristic cell types: mucus secreting, epidermoid and intermediate. We encountered two cases displaying unusual cytologic features, including clear intranuclear inclusions. CASES: Two females, aged 33 and 39, presented with an intrabronchial tumor and pulmonary parenchymatous mass, respectively. Fine needle aspiration of both tumors showed similar cytologic features, with a dominant population of cells with bland nuclei and wide cytoplasm, and frequent intranuclear inclusions. A minor component of mucus-secreting cells was also recognized. Histologically, both tumors corresponded to the clear cell variant of mucoepidermoid carcinoma. CONCLUSION: The cytologic picture in our cases has not been described previously in fine needle aspirates of mucoepidermoid carcinoma, in neither the bronchus nor salivary gland. The differential diagnosis of a monotonous population of epithelial cells with intranuclear inclusions involves bronchioloalveolar carcinoma, but the absence of the characteristic sheet pattern, as well as the clinical and image findings, excludes this possibility. The lack of atypia and intrabronchial location limits the scope to carcinoid and salivary gland-type tumors of the bronchus. Since we were aware of the possibility of unusual cytologic presentations of mucoepidermoid carcinomas, search for different cellular populations suggested the precise diagnosis.

Mucoepidermoid carcinoma arising in Warthin's tumour of the parotid gland: report of two cases with histopathological, ultrastructural and immunohistochemical studies.

AIMS: Malignant transformation of Warthin's tumour (WT) is a rare event. We present two cases of mucoepidermoid carcinoma (MEC) arising in WT in the parotid gland. METHODS AND RESULTS: Two cases of MEC arising in WT, which were found in 185 cases of WT of the parotid gland, were investigated by light and electron microscopy, and immunohistochemistry. Both cases had largely similar macroscopic and histological features with some differences. Histologically, the tumours consisted mainly of WT with multilayered hyperplastic arrangements of oncocytic cells and focal squamous and goblet cell metaplasia. In the same tumour mass, however, the features of MEC were observed with invasion to adjacent adipose tissue. A transitional zone between WT and MEC was evident. Both patients were alive and well without evidence of recurrence 30 and 34 months after surgery, respectively. Electron microscopy revealed that cyst lining epithelial cells in WTs had abundant mitochondria whereas some of the MEC cells contained numerous tonofilaments and mucinous granules. Immunohistochemically, oncocytic cells of WTs were strongly positive for mitochondria and SalylTn was extensively stained in MECs. The labelling index for Ki67 was obviously higher in the carcinoma cells than the epithelial cells of WT. CONCLUSIONS: Our cases confirmed the possibility of malignant transformation of the epithelial component in WT to MEC.

Naturally occurring mucoepidermoid carcinoma in the submandibular salivary gland of two mice.

Mucoepidermoid carcinomas in two mice were investigated histologically, immunohistochemically and ultrastructurally. The neoplastic cells showed divergent differentiation into periodic acid-Schiff-positive mucous cells, keratin-positive squamous cells, and cells with both mucous granules and sheaves of tonofilaments. Gland formation and keratinization were not observed. At the periphery of tumour cell nests, some cells were immunolabelled for smooth muscle actin or contained concentrated thin filaments, and these observations were interpreted to indicate that murine mucoepidermoid carcinomas are associated with both myoepithelium and duct epithelium.

[Clinico-morphologic characterization of mucoepidermoid carcinoma of the salivary glands]. / Kliniko-morphologicheskaia kharakteristika mukoépidermoidnoi kartsinomy sliunnykh zhelez.

64 cases of SGMC were studied. Clinical morphology of epidermoid carcinoma was studied according to the 2nd edition of the International histologic classification of the tumors of this site (WHO, Geneva, 1990). This allows to study not only incidence of this tumor depending on the site, sex and age, but to give new data on its biology. The malignancy of all the three types of this tumor (of low, moderate and high grade) was confirmed by means of histologic, histochemical, electron-microscopic (EM) and EM-histochemical methods. The previous assumption on benign character of the low-grade variant of the tumor was not confirmed.

Papillary variant of low-grade mucoepidermoid carcinoma--an unusual bronchial neoplasm. A light microscopic, ultrastructural, and immunohistochemical study.

The authors report an unusual bronchial papillary tumor found in the right lower lobe of a 89-year-old woman at the time of postmortem examination. The lesion was difficult to classify and did not fit well into any lung neoplasm category. Light and electron microscopic features were consistent with a papillary variant of low-grade mucoepidermoid carcinoma. Differential diagnoses mainly included the papillary bronchial mucous gland adenoma and the mixed epithelial-cell-type papilloma. Histogenetically, the tumor appeared to originate from the surface epithelium. Because the lesion showed features of low malignant potential, lobectomy would constitute an appropriate therapy whenever possible.