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.