CLINICOPATHOLOGICAL AND IMMUNOHISTOCHEMICAL CHARACTERISTICS OF BRONCHIAL GLAND CELL TYPE ADENOCARCINOMA OF THE LUNG

Twenty-three cases of bronchial gland cell (BGC) type lung adenocarcinoma were examined clinicopathologically and immunohistochemically. BGC type adenocarcinoma was defined as adenocarcinoma showing histologic and cytologic differentiation toward the bronchial gland. This type of adenocarcinoma occurred more frequently in younger patients (mean age, 50.5 years) than in patients with other types of adenocarcinoma (mean age, 60.1 years). It had a tendency to arise from relatively large bronchi and show endobronchial growth. However, there was no difference in disease stage based on tumor, nodal involvement, metastases (TNM) factors and outcome between BGC type adenocarcinoma and peripheral type adenocarcinoma. Immunohistochemically, 50%, 68%, and 64% of BGC type adenocarcinomas were positive for carcinoembryonic antigen, surfactant apoprotein, and secretory component, respectively. Peripheral type adenocarcinomas showed similar rates of immunohistochemical stainability of these antigens. The positive reaction of BGC type adenocarcinomas with anti-surfactant apoprotein antibody may indicate maintenance of traces of differentiation toward peripheral airway epithelium. Lactoferrin is characteristically detected in BGC type adenocarcinomas, although the positive rate was not very high.