Oat cell carcinoma manifesting as a bronchocele.

Three cases of oat cell carcinoma appearing as a bronchocele on the chest radiograph are described. A bronchocele as the major radiologic manifestation of oat cell carcinoma has not been emphasized previously. Such a bronchocele may be filled with neoplastic cells rather than only inspissated mucus. Needle aspiration biopsy was definitive in two of the cases when conventional diagnostic methods failed.