Tumors, Benign

Benign tumors of the lung and pleura encompass a wide variety of epithelial and nonepithelial tumors that have an excellent prognosis in general. Many of these lesions are discovered incidentally in chest radiographs carried out for other reasons, most being asymptomatic at the time of presentation. Such benign tumors can occasionally produce symptoms related to bronchial obstruction (e.g., bronchial papillomas and mucous cell adenomas), or because of compression of lung parenchyma by sizable tumors (such as large solitary fibrous tumors of pleura/lung). Symptoms when present may include hemoptysis, cough or dyspnea, and other manifestations only rarely. Only exceptionally do benign lesions of the bronchus undergo malignant transformation (specifically the development of squamous cell carcinoma in tracheobronchial papillomatosis). In part, the importance of benign tumors of lung and pleura lies in the necessity to discriminate between them and malignant neoplasms of the respiratory tract.