Bronchial Carcinoids and Bronchial Gland Carcinomas

Bronchial carcinoid and bronchial gland carcinomas are rare airway-related thoracic malignancies. Carcinoid is a neuroendocrine neoplasm and comprises 1-2 % of primary lung cancers. Affected patients are younger than those with lung cancer, and may present with signs and symptoms of airway obstruction including cough, hemoptysis, wheezing, and recurrent pulmonary infection. Carcinoid typically manifests as a central nodule or mass and may cause post obstructive atelectasis or pneumonia. On imaging these lesions are usually well marginated pulmonary nodules or masses and may be completely endobronchial, partially endobronchial or may abut an airway. Typical carcinoid often exhibits an indolent behavior and carries a good prognosis with complete surgical excision. Atypical carcinoid is similar to typical carcinoid on imaging but has a more aggressive behavior and may be associated with metastatic intrathoracic lymphadenopathy. Bronchial gland carcinomas include adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC). ACC is the second most common primary tracheal malignancy and manifests as an endoluminal tracheal nodule or as circumferential tracheal narrowing. MEC typically affects segmental bronchi and may be indistinguishable from carcinoid on imaging. Although these lesions may exhibit an indolent course, they are locally invasive malignancies, and affected patients have a variable prognosis.