Bronchial carcinoid tumors.

Bronchial carcinoid tumors, termed (incorrectly) "bronchial adenomas" in the past, are uncommon pulmonary neoplasms. These tumors are currently classified as neuroendocrine in origin because of their potential to form and sometimes secrete a variety of chemical substances. Overall, approximately 75% of bronchial carcinoid tumors arise in the lobar bronchi, 10% occur in the main-stem bronchi, and 15% originate in the periphery of the lung. Well-differentiated carcinoid tumors constitute almost 90% of all bronchial carcinoids. Atypical carcinoid tumors have a higher malignant potential than do typical bronchial carcinoids. The carcinoid syndrome is rarely, if ever, associated with carcinoids limited to the tracheobronchial tree. Occasionally, Cushing's syndrome due to ectopic hormone production is caused by bronchial carcinoid tumors. More than 75% of bronchial carcinoids are detected on conventional posteroanterior chest roentgenograms. Computed tomography may help disclose small neoplasms that are occult on conventional roentgenography, particularly in the assessment of patients who have Cushing's syndrome due to ectopic hormone production. Pulmonary resection is the treatment of choice for bronchial carcinoids. The prognosis is related to the pathologic grade and stage of the tumor.