Thoracic outlet syndrome caused by first rib hemangioma

We report a case of first rib hemangioma that caused thoracic outlet syndrome. A 50-year-ole woman who was admitted to our hospital with a clinical diagnosis of thoracic outlet syndrome presented with fullness and easy fatigue of her right arm. Her right arm discomfort was associated with intermittent engorgement of superficial veins over the shoulder girdle. A chest radiograph revealed an enlargement of the anterior aspect of the first rib with fine bony trabeculations. Computed tomography scan showed contrast enhancement over the enlarged rib. Our tentative preoperative diagnosis was a benign first rib hypertrophic change, such as an old fracture with exuberant callus formation. A right-arm venogram revealed a patent subclavian vein with an extrinsic compression, which occluded on arm abduction. The findings of neural conduction studies of both upper extremities were symmetric and normal. The patient agreed to surgery because of the occlusive condition of the subclavian vein on arm abduction and progressive arm weakness in recent months. Segmental transection of the offending portion of the enlarged first rib was complicated by difficulty in isolating the whole length of the compressed but normal-appearing subclavian vein by our initial transaxillary and infraclavicular approaches because the medial aspect of the subclavian vein was obstructed by the enlarged first rib, which extended medially to the junction of the right jugular and subclavian veins. Successful segmental transection of the enlarged first rib was finally accomplished by combined transaxillary, infraclavicular, and supraclavicular approaches. A moderate amount of rib bleeding from resection ends was noted during segmental resection of the enlarged first rib, resulting in local hematoma formation. A 470-mL bloody discharge was collected from the vacuum ball inserted via the transaxillary route during her 12-day hospitalization. Pathologic examination revealed an intraosseous hemangioma. The patient had a prolonged course to partial recovery of her arm numbness, but signs of venous compression were much improved at 6 months' follow-up. Although hemangioma is benign, its hypervascular nature may cause catastrophic intraoperative bleeding.