Anterior mediastinal masses deserve prompt diagnosis to rule out malignant conditions. We review the literature and present a rare case of benign cavernous hemangioma of the anterior mediastinum.
The patient was a 57-year-old male who was referred for evaluation of an anterior mediastinal mass. His past medical history was significant for colon cancer treated with adjuvant chemotherapy two years earlier, hypertension, paroxysmal atrial fibrillation refractory to multiple cardioversion attempts, for which he was on Coumadin. He was a former 16-pack year smoker with an allergy to contrast dye.A chest CT revealed a 6.3 x 4.10 cm mass in the anterior mediastinum with marked circumferential calcification. Hounsfield units were consistent with a soft tissue mass. Physical exam revealed an irregular cardiac rate and rhythm but was otherwise normal. A cardiac stress test showed no signs of ischemia and no evidence of hemodynamically significant coronary artery disease. The radiological report concluded that the lesion was most likely consistent with thymoma, with possible consideration of a calcified thymic cyst. The mass was resected through a left parasternal approach with resection of the 3rd cartilage. The mass adhered to the left thymic pole, left pleura and underlying pericardium, all of which was resected en bloc. . The chest tube was removed on postoperative day #1 and the patient was discharged home on postoperative day #2. Pathology revealed a calcified cavernous hemangioma with associated secondary changes. It measured 7.9 x 5.4 x 4.2 cm. (68.2 g). Microscopic examination revealed multilocular cysts representing interconnected vascular spaces. Focally, there was a prominent lymphoplasmacystic infiltrate with active fibrosis and cholesterol deposition. There was no evidence of malignancy.
Hemangiomas are rare mediastinal tumors. They account for 0.5% of mediastinal masses. Anatomically they may arise in the anterior or posterior mediastinum. They are categorized as capillary, cavernous, and venous. Microscopically they are formed by dilated vessels, lined by endothelial cells, with fibrous septae. They might contain fat, fibrous tissue, localized areas of thrombus, cholesterol deposition, and calcification. Dr. Goldstraw reports that patients may present with symptoms suggestive of advanced malignancy, like hoarseness, recurrent pleural effusions, and superior vena cava obstruction. These lesions have not been found to be prone to malignant degeneration. VATS resection was not possible in this case since the osseous shell mandated a portal incision at least the diameter of the tumor. Symtoms from these tumors arise from compression of adjacent structures. These vascular tumors have been treated in children with alpha-2a interferon. These might be used to reduce the volume of a bulky tumor and increase the safety in patients with vital structure encasement.Differential diagnosis of calcified mediastinal masses are calcified thymic cysts, recurring tracheal leiomyoma, mediastinal teratoma, and calcified lymph nodes usually due to fungal disease.
Most anterior mediastinal masses are malignant, and should be biopsied. Incisional biopsy was precluded in this case due to the calcified shell. Excisional biopsy through a limited incision allowed complete removal of the tumor. Allows resolution of associated compression symptoms, and establishes the diagnosis with certainty.
Luis Argote-Greene, None.