Benign Epithelial Tumors of the Lung

Benign tumors of the lung are much less common than malignant tumors with an incidence ranging from 1% to 5% of all lung tumors (Yoon et al. J Comput Assist Tomogr. 26:784-796, 2002). These neoplasms are generally small and depending on their site or origin can be associated with symptoms such as cough, postobstructive pneumonia, and hemoptysis if endobronchial in location or produce no symptoms if located in the peripheral lung parenchyma. Most of these tumors are mesenchymal in origin, mainly comprising hamartomas (Borczuk, Arch Pathol Lab Med. 132:1133-1148, 2008). Only a small subset of benign pulmonary tumors is epithelial in nature. Lack of familiarity with these tumors may lead to diagnostic challenges and potential misdiagnosis with significant consequences for patient care. In this chapter, a comprehensive review of benign epithelial tumors of the lung is presented along with discussion of the most important differential diagnosis.