Gorham-Stout disease (GSD) is a rare disease of massive osteolysis associated with proliferation and dilation of lymphatic vessels. GSD may affect any bone in the body and can be monostotic or polyostotic. Symptoms at presentation are dependent upon the location(s) of the disease; the most common symptom is localized pain. The disease may be discovered after a pathological fracture. The disease is Monarch Disease Ontology identifier MONDO_0007414 (Gorham-Stout disease). Also known as: Gorham disease, Gorham syndrome, idiopathic massive osteolysis, progressive massive osteolysis, vanishing bone disease.