Merck Manual

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Bronchial Carcinoid


Robert L. Keith

, MD, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine

Reviewed/Revised May 2023

Bronchial carcinoids are rare (1 to 2% of all lung cancers in adults), slow-growing, neuroendocrine tumors arising from bronchial mucosa; they affect patients in their 40s to 60s.

Carcinoid tumors Overview of Carcinoid Tumors Carcinoid tumors develop from neuroendocrine cells in the gastrointestinal tract (90%), pancreas, pulmonary bronchi, and rarely the genitourinary tract. More than 95% of all gastrointestinal... read more develop from neuroendocrine cells in the gastrointestinal tract (90%), pancreas, pulmonary bronchi, and rarely the genitourinary tract. Although carcinoids are often benign or only locally invasive, those affecting the bronchus are frequently malignant. Some carcinoid tumors are endocrinologically active; the likelihood varies by site of origin and is highest for tumors originating in the ileum and proximal colon (40 to 50%) and lower with bronchial carcinoids.

Half of patients with bronchial carcinoid 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.

Carcinoid syndrome symptoms include

  • Flushing

  • Diarrhea

  • Bronchospasm

Chronic sequelae of carcinoid syndrome include

  • Telangiectasias

  • Right-sided valvular heart disease

  • Retroperitoneal fibrosis

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 gastrointestinal carcinoids).

Diagnosis of Bronchial Carcinoid

  • Bronchoscopic biopsy

Diagnosis of bronchial carcinoid 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.

Treatment of Bronchial Carcinoid

  • Surgery

Treatment of bronchial carcinoid is with surgical removal with or without adjuvant chemotherapy and/or radiation therapy.

Prognosis depends on tumor type. Five-year survival for well-differentiated (typical) carcinoids is > 90% in most series, but lower for atypical tumors.

Drugs Mentioned In This Article

Drug Name Select Trade
Bynfezia, Mycapssa, Sandostatin, Sandostatin LAR
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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