대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Mediastinal Cavernous Hemangioma

Radiologic Findings

Chest radiograph shows abnormal bulging of the mediastinum at aortopulmonary window area, lateral to the aortic arch and left main pulmonary artery. Contrast-enhanced CT scans show an well-marginated anterior mediastinal mass showing heterogeneous enhancement and punctate calcification.

Brief Review

Mediastinal hemangioma is rare, benign vascular tumor that account form less than 0.5% of all mediastinal masses. At histologic examination, these tumors are composed of large, interconnecting vascular spaces lined by a flattened cuboidal epithelium. The tumors have varying amounts of interposed stromal elements (eg, fat, myxoid, and fibrous tissue) and focal areas of organized thrombus. The thrombi may calcify as phleboliths. The tumors are categorized according to the size of their vascular spaces as capillary, cavernous, or venous hemangiomas. True hemangiomas are always benign, but histologic examination must be performed to differentiate them from potentially malignant vascular tumors such as hemangioendotheliomas and hemangiopericytomas.
Mediastinal hemangioma typically occur in young patients; approximately 75% manifest before the age of 35 years. One-third to one-half of patients have no symptoms at presentation; the remainder present with nonspecific symptoms such as a cough, chest pain, and dyspnea due to compression or, less likely, invasion of adjacent structures.
Mediastinal hemangiomas usually involve anterior or posterior mediastinum. These lesions may extend into the neck or abdomen. Phleboliths, a potentially diagnostic finding, are seen in only 10% of cases on plain radiography. On CT scan, most hemangiomas manifest as well-marginated mass but may be diffusely infiltrative mass. The mass is usually heterogeneous (83%) on unenhanced scan and shows heterogeneous enhancement after contrast enhancement (91%). CT scan is more sensitive than radiography to demonstrate phlebolith (7%) or nonspecific punctate calcification (21%) of the mass. The signal characteristics at MRI may be nonspecific but may show the more specific appearance of multiple high-signal foci of methemoglobin formation following hemorrhage in both T1- and T2-weighted images.

References

1. McAdams HP, Rosado-de-Christenson ML, Moran CA. Mediastinal hemangioma: radiographic and CT features in 14 patients. Radiology 1994; 193:399-402
2. Ishii K, Maeda K, Hashihira M, Miyamoto Y, Kanegawa K, Kusumoto M, Kono M, Nishiyama S. MRI of mediastinal cavernous hemangioma. Pediatr Radiol 1990;20:556-7

Keywords

Mediastinum, Benign tumor,