Chronic expanding haematoma caused by rib fractures after radiation therapy.

A chronic expanding haematoma is characterised by progressive enlargement over months to years and can develop in various locations. Herein, we report a surgically resected chronic expanding haematoma from the left thoracic outlet, which was caused by rib fractures owing to a late-phase complication of radiation therapy for pulmonary metastasis. A man in his 60s, who had undergone multiple lung resections and radiation therapy, presented with left shoulder pain and left-hand numbness. The imaging studies revealed a space-occupying mass and old rib fractures in the irradiated area; the needle biopsy determined it was a haematoma. Subsequently, we resected the haematoma and achieved haemostasis via a supraclavicular approach without the need for rib resection. The patient's neurological symptoms were relieved immediately after surgery, and haematoma regrowth was not observed 1 year after surgery.