Excision of Giant Chronic Expanding Hematoma of the Thorax Caused by Rib Fractures after Proton Radiotherapy for Lung Cancer.

Chronic expanding hematoma (CEH) is defined as a hematoma that gradually expands over months to years. An 82-year-old female underwent proton radiotherapy for left upper lobe lung cancer 10 years previously. Two years after the therapy, a hematoma developed from the left 3rd to 5th dorsal rib fractures and gradually expanded, causing contraction of the left shoulder. Transcatheter arterial embolization was performed; however, the hematoma continued to expand with thrombocytopenia, and the platelet was decreased to 4.2 × 10⁴/μL. Computed tomography showed a 17.2 × 14.0 × 10.0 cm mass between the left scapula and left dorsal ribs. The CEH of the thorax was completely excised with combined resection of the 3rd to 5th ribs, while the brachial plexus was preserved. Postoperatively, the platelet completely recovered and she could raise her left arm. A complete excision with surrounding organs preserved is the strategy used in the treatment of CEH of the thorax.