OBJECTIVE: Pulmonary tumorlets are defined in pathologic terms as benign localized neuroendocrine cell proliferations a few millimeters in size that are usually associated with damaged and ectatic small airways. The purpose of this study was to determine the frequency with which pulmonary tumorlets can be seen on CT and to describe their CT appearance. CONCLUSION: In 33 patients with proven tumorlets, a nodule was visible on CT in the same region as that of the resected specimen. Despite its ominous-sounding name, a pulmonary tumorlet represents benign tissue that may manifest as a subcentimeter pulmonary nodule and should be considered in the differential diagnosis of small pulmonary nodules visible on CT.
