대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Mediasitnal hamartoma

Radiologic Findings

Figs 1. Chest PA shows left hilar enlargement.
Fig 2-4. Mediastinal setting images of the pre- and post-contrast chest CT scan show sharply demarcated soft tissue mass with mild enhancement (about 5 HU) in the left hilum. There is no internal calcification in this mass.
Figs 5. FDG-PET scan shows mild FDG (SUVmax 2.1) uptake of this mass.

Brief Review

Pulmonary hamartoma was thought to be a neoplastic malformation, but recently, it is considered to be a benign tumor, composed of tracheal epithelium and mesenchymal tissue around the bronchus. Most hamartomas are located in the periphery of the pulmonary parenchyma, but 1% to 20% may occur as endobronchial lesions and cause symptoms related to bronchial obstruction. Pulmonary hamartoma is a relatively common lesion that is usually discovered as an incidental, rounded focus of increased opacity on a routine chest film. These are benign tumors more common in males, with a peak incidence in the seventh decade of life.
In about one-third of the cases, characteristic popcorn-like calcification is seen radiologically. There is clinical, morphological, and radiological evidence to suggest that this lesion is acquired and that it represents a primary overgrowth of mesenchymal tissue of the bronchial wall, with secondary entrapment of the bronchial epithelium in the more peripheral lesions.
Hamartoma occurring in the mediastinum is extremely rare, and only several cases have been reported; in a series of 215 cases of pulmonary hamartoma reported from the Mayo Clinic, none of them was located in the mediastinum. Whether mediastinal hamartomas may be described as primary mediastinal tumors or lesions that have migrated through the pulmonary parenchyma is not fully understood and is open to speculation.

References

1. Gjevre JA, Myerus JL, Prakash UB: Pulmonary hamartoma. Mayo Clin Proc 1996; 71: 14~20.
2. Kim JY, Hofstetter WL: Tumors of the mediastinum and chest wall. Surgical Clinics of North America, 2010-10-01, Volume 90, Issue 5, Pages 1019-1040.
3. Gluck MC, Moser KM: Hamartoma of the lung presenting as a mediastinal mass. American Review of Respiratory Disease, 1968 vol 98, No 2, 281~282.
4. Jayaprakash Balakrishnan, Deepu Maniyan, Nileena Nayak et al. Lung India. 2015 Nov-Des;32(6):665~666.

Keywords

Mediastinum, Benign tumor, Hamartoma,