Two cases of Gorham-Stout disease with good response to zoledronic acid treatment.

Gorham-Stout disease - also called vanishing bone syndrome - is a rare bone disease characterized by a progressive intra-osseous proliferation of non-neoplastic vascular tissue resulting in massive osteolysis. Here, we report two clinical cases of Gorham-Stout disease. Case 1: a 56-year-old woman with 20 years of history of pain and swell in elbows, ankles and wrist. Then she was diagnosed as systemic lupus erythematosus (SLE) with glomerulonephritis type III. After other pathologies were ruled out Gorham-Stout disease was diagnosed. Intravenous zoledronic acid (5 mg) was indicated and after third infusion a progressive improvement of pain, mobility and daily activities were observed. Case 2: a 70-years-old man with a history of pain and limited motion in the left shoulder without X-ray abnormality. Six months later pathological fracture in the left humerus occurred and after ruled out other pathologies Gorham-Stout disease was diagnosed. Intravenous zoledronic acid (5 mg) was indicated and a good response was observed after the first infusion. Nowadays just over 200 cases were reported. Gorham-Stout disease was reported in different bones, at different age presentation and severe physical deformities, disabilities, and life-threatening complications can occur. Two cases of Gorham-Stout disease with good response to zoledronic acid was reported in this article.