Recognition of the so-called bronchial adenoma as an entity distinct from bronchogenic carcinoma is credited to Kramer1 and to Wessler and Rabin.2 Early classifications of these lesions included carcinoid and cylindroid (adenocystic) varieties. The historical development of their nomenclature has been reviewed3 recently and, as the behavioral characteristics of the group have unfolded over the past quarter of a century, it has become increasingly apparent that the term "adenoma" inaccurately connotes their capacity for local invasion, extension, and distant metastasis.4-10 It would seem reasonable, therefore, to dispense with the term "adenoma" and its misleading implications of benignity and to refer to these lesions simply as carcinoid and cylindroid bronchial tumors. A more recently defined group of mucoepidermoid bronchial tumors3,11,12 exhibits somewhat similar behavior and is currently classified as a variant form of cylindroma.
Carcinoid bronchial tumors occur with much greater frequency than cylindromas. Moersch and