Mediastinal hemangiomas: Spectrum of CT and MRI findings - retrospective case series study and systematic review of the literature.

Purpose: To analyze the imaging manifestations of mediastinal hemangioma (MH) by CT and MRI to aid in its successful diagnosis and preoperative evaluation.

Methods: Seventeen cases of MH diagnosed by histopathology combined with CT and MRI were retrospectively collected; and their CT and MRI features, including the lesions' site and range, shape, size, margin, density or signal, enhancement pattern, mass-cardiovascular interface, mass-pulmonary interface, and other characteristics were evaluated.

Results: The anterior, middle, and posterior mediastinum were involved in 13, 13, and 8 cases, respectively. The masses size varied from 20 to 233 mm. Irregular, dumbbell-like, and oval masses were found in 13, 2, and 2 cases, respectively, while with pampiniform growth in 16 cases and expansive growth in 1 case. Mixed density, homogeneous density solid masses, and heterogeneous density masses with dominant fat were found in 9, 5, and 3 cases, respectively, showing mild or significant enhancement in aortic phase while no or mild enhancement in pulmonary artery phase. Draining veins were found in 16 cases and feeding arteries in 10 cases. Phleboliths were detected in 10 cases, splenic hemangiomas in 6 cases, and left lateral-chest-wall hemangioma in 1 case. In MRI sequences, mixed signal was found on TWI and heterogeneous hypersignal with nodular or linear hyposignal on TWI in 5 cases, mild or significant enhancement in 4 cases, draining veins in 2 cases, and no feeding arteries or phleboliths were seen.

Conclusion: Presence of phleboliths, pampiniform growth pattern, and aberrant draining veins are relatively specific characteristics in diagnosing MH.