Pulmonary hamartoma mimicking a mediastinal cyst-like lesion in a heavy smoker

Pulmonary hamartoma (PH) is the most common benign tumor of the lung, typically presenting as a peripheral solitary nodule with round shape and smooth margins. The main computed tomography (CT) features that allow a confident diagnosis of PH are intranodular fat and popcorn-like calcifications. However, the presence of these features within PHs is variable. Thus, a reliable diagnosis of PH cannot be formulated in approximately 30% of cases. Furthermore, PHs may occasionally show atypical CT features. The present article reports the case of a centrally located PH with an extremely rare and previously unreported CT presentation consisting of fluid attenuation, rim enhancement and thick enhancing septa that mimicked a mediastinal cyst-like lesion.