Bronchial carcinoids are rare, slow-growing neuroendocrine tumors arising from bronchial mucosa; they affect patients in their 40s to 60s.
Half of patients are asymptomatic, and half present with symptoms of airway obstruction, including dyspnea, wheezing, and cough, which often leads to a misdiagnosis of asthma. Recurrent pneumonia, hemoptysis, and chest pain are also common.
Paraneoplastic syndromes, including Cushing syndrome due to ectopic ACTH, acromegaly due to ectopic growth hormone–releasing factor, and Zollinger-Ellison syndrome due to ectopic gastrin production, are more common than carcinoid syndrome, which occurs in < 3% of patients with the tumor.
A left-sided heart murmur (mitral stenosis or regurgitation) due to serotonin-induced valvular damage occurs rarely with bronchial carcinoids (as opposed to the right-sided valvular lesions of GI carcinoid).
Diagnosis is based on bronchoscopic biopsy, but evaluation often initially involves chest CT, which reveals tumor calcifications in up to one third of patients.
Indium-111–labeled octreotide scans are useful for determining regional and metastatic spread.
Increased urinary serotonin and 5-hydroxyindoleacetic acid levels support the diagnosis, but these substances are not commonly elevated.