Abstract
Gorham-Stout disease (GSD) is an extremely rare musculoskeletal disease of unknown aetiology characterised by non-neoplastic proliferation of vascular and lymphatic channels causing massive osteolysis, typically affecting younger individuals. Chylothorax is a known complication of GSD which is postulated to occur from thoracic spine involvement leading to pleural or thoracic duct invasion. In our case, bilateral chylothorax developed in a 60-year-old woman without any thoracic spine involvement of her disease, challenging the proposed mechanism. Despite bilateral pleural drainage and escalating doses of sirolimus, she ultimately developed respiratory failure and shock and succumbed to her illness. Overall survival of GSD is unknown, but when complicated by chylothorax, prognosis is typically poor. GSD represents a diagnostic and management challenge due to the paucity of knowledge surrounding its aetiology and management. These patients require multidisciplinary coordinated care. It is also important to note its high mortality when associated with chylothorax in particular.