Benign hemangiomas account for less than 0.5% of mediastinal masses. While a preoperative diagnosis is difficult using noninvasive means, an MRI study proved useful for suggesting the correct diagnosis. We report a 27-year-old patient with a huge cervicomediastinal mass (25X15X15 cm) with compression of the entire right lung, extending into the spinal canal and the neck, and enveloping the right subclavian vessels. Total excision of the tumor was done by a neurosurgeon and chest surgeon, using both posterior and anterior approaches. A hemangioma, even though very rare, may present as a mass in the neck, and should be considered in the differential diagnosis of neck and mediastinal masses.