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Adenoid cystic (cylindromatous) carcinoma of the trachea: an ultrastructural study

Adenoid cystic (cylindromatous) carcinoma of the trachea is a rare tumour. The histological features in previously reported cases have been widely variable; only one previous ultrastructural study has been undertaken. Three cases are reported in the present study and the ultrastructural findings are reviewed. The tumours were composed of two types of cells, mature ductal and immature myoepithelial. The cylindromatous stroma appeared as a fibrillar substance which was also found between the undifferentiated myoepithelial cells and appeared to be a product of these cells.