Case Reports—PulmonaryMesenchymal Cystic Hamartoma of the Lung MRI and PET/CT AppearanceSouza, Frederico F. MD*; Chen, Eleanor MD, PhD†Author Information *Department of Radiology, Dana Farber Cancer Institute †Department of Pathology, Brigham and Women's Hospital, Boston, MA Reprints: Frederico F. Souza, MD, Department of Radiology, Dana Farber Cancer Institute, 44 Binney Street, Boston, MA, 02215 (e-mail: [email protected]). The work was performed at the Dana Farber Cancer Institute. Journal of Thoracic Imaging: February 2009 - Volume 24 - Issue 1 - p 52-55 doi: 10.1097/RTI.0b013e31818c8834 Buy Metrics Abstract We report the magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) findings of a patient who presented with lower thoracic pain, nausea, and vomiting and had a CT scan of the chest in which a well-defined homogeneous mass was identified. Further evaluation with MRI and PET/CT showed a nonenhancing homogeneous paraspinal mass in the left lung base involving the left hemidiaphragm. The mass showed lack of enhancement on MRI and was photopenic on PET/CT. Video-assisted thoracoscopic surgery and resection of the mass was performed and showed a mesenchymal cystic hamartoma invading the left hemidiaphragm. Such a growing hamartoma with pleural and diaphragmatic invasion is very atypical and to our knowledge, has not been previously reported. © 2009 Lippincott Williams & Wilkins, Inc.