Neuroendocrine cells in dysplastic bronchi: ultrastructural observations and quantitative analysis of secretory...

Ultrastructural and biochemical studies have suggested that bronchopulmonary carcinoids and oat cell carcinomas may be derivatives of neuroendocrine cells; their amine and/or peptide secretory capabilities may at times be reflected in clinical hormonal syndromes. This investigation was prompted by the hypothesis that dysplastic neuroendocrine bronchial cells may also exhibit structural and functional aberrations of their secretory apparatus. Surgical specimen samples from 5 human dysplastic bronchi were studied ultrastructurally; 7 normal bronchi served as controls. Golgi complexes of dysplastic cells were distinctly less prominent than those of the controls. Moreover, the Golgi vesicles of dysplastic cells appeared significantly smaller than their counterparts in normal cells (P less than 0.01). Also, dysplastic neuroendocrine cells displayed significantly fewer secretory granules per cell than the controls (P less than 0.05). These findings indicate structural abnormalities in the secretory apparatus of neuroendocrine cells in dysplastic bronchi and correlate with experimental observations of aberrant hormonal production associated with bronchial dysplasia. Thus, the possibility arises that bronchial epithelial dysplasias may be detected and monitored through laboratory determinations of their secretory products.