Abstract
Mucoepidermoid tumors originating in the bronchial gland assumed to be rare. Recently, we have had the opportunity to examine6cases of the tumors. Their symptoms and X-ray findings would not appear to be significantly different from those presented in bronchogenic carcinoma. Two of 6 cases were of low-grade malignancy, while the others showed high-grade malignancy, so we asserted that these tumors were treated as the other bronchogenic carcinoma.
On exfoliative cytology of sputum, malignant cells were identified in all cases; dense cytoplasm with vacuoles or with enlarged nucleoli were characteristic.
Light microscopically, round or oval tumor cell nests with a dense fibrous stroma were observed.The cell nests consisted of both squamous and mucous cells. The epidermoid elements proliferated in solid sheets, while the mucinsecreting cells tend to line cystic spaces. Mucin were abundant in most tumors, both intra-and extracellulary. Morphological transition to adenoid cystic carcinoma or giant cell carcinoma was detected in some sites.
Electron microscopically, the tumor cells showed a simillar arrangement to bronchial gland epithelium. The tumor cells were connected each other with thick desmosomes.Abundant tonofilaments together with mucousproducing granules were found in the same tumor cells. We would like to conclude that the cells of bronchial mucoepidermoid tumors had both carac teristics of epidermoid and adenocarcinoma.
