Thoracic carcinoids: radiologic-pathologic correlation.

Carcinoids are neuroendocrine neoplasms. Bronchial carcinoids are unusual, malignant primary neoplasms that characteristically involve the central airways and typically exhibit well-defined margins and bronchial-related growth. Bronchial carcinoids include low-grade typical carcinoids and the more aggressive atypical carcinoids. These tumors usually affect patients in the 3rd through 7th decades of life who are often symptomatic with cough, hemoptysis, or obstructive pneumonia. Bronchial carcinoids radiologically manifest as hilar or perihilar masses, with or without associated atelectasis, pneumonia, bronchiectasis, or mucoid impaction. At computed tomography, an anatomic relationship of these tumors to a bronchus is usually seen, and they may show contrast material enhancement or calcification. In rare cases, carcinoids occur in the thymus; when they do, they are aggressive tumors that affect adults who usually present with chest pain, cough, and dyspnea. Thymic carcinoids manifest radiologically as anterior mediastinal masses and may mimic thymomas. Thoracic carcinoids are treated by surgical excision. The prognosis for patients with typical bronchial carcinoids is excellent; patients with atypical bronchial or thymic carcinoids have a worse prognosis.