Mixed glandular and squamous-cell carcinoma of the bronchus.

A group of 26 examples of lung carcinoma showing mixed squamous and glandular differentiation is described. The clinical and biological features of the lesions are intermediate between those of squamous-cell carcinoma and adenocarcinoma of the bronchus. It is suggested that bronchial carcinoma is a single entity in which the type of cell, whether glandular or squamous, plays a much smaller part in determining the biological behaviour than the anatomical site of the tumour and the degree of differentiation of its component cells. It is suggested that mixed adenosquamous tumours arise from bronchial epithelial cells in the process of metaplastic change from the columnar to the squamous form.