9-19: Bronchial Carcinoid Tumors

Bronchial carcinoid tumors are malignant low- and intermediate-grade neuroendocrine tumors of the lung, with a favorable prognosis compared to high-grade neuroendocrine tumors such as small cell lung cancer. Bronchial carcinoids typically occur as pedunculated or sessile growths in central bronchi. Common symptoms are hemoptysis, cough, focal wheezing, and recurrent postobstructive pneumonia. Peripherally located tumors are rare and present as asymptomatic solitary pulmonary nodules. Carcinoid syndrome (flushing, diarrhea, wheezing, hypotension) and paraneoplastic Cushing syndrome are rare. Fiberoptic bronchoscopy may reveal a pink or purple tumor in a central airway. These lesions have a well-vascularized stroma, and biopsy may be complicated by significant bleeding. CT scanning is helpful to localize the lesion and to follow its growth over time. Octreotide scintigraphy is also available for localization of these tumors.

Bronchial carcinoid tumors grow slowly; the aggressiveness is determined by the cell histology, with “typical carcinoid,” a low-grade tumor, demonstrating a more indolent and favorable course than “atypical carcinoid,” an intermediate-grade tumor. Bronchial carcinoid tumor staging follows the same TNM classification as other lung cancers. Surgical excision, including lymph node dissection and resection, is recommended for localized disease, and the prognosis is generally favorable. Most bronchial carcinoid tumors respond poorly to radiation and chemotherapy (see Part 41).

Adenomas, carcinomas, and other malignancies may rarely metastasize to the bronchi and present with endobronchial lesions. Hamartomas, myxomas, and amyloid are other rarer entities in the differential diagnosis of endobronchial mass lesions.