We report an 81-year-old female with rheumatoid arthritis who suVered from “vanishing bone disease or Gorham’s disease” involving the right humeral head. In 2003, she was diagnosed of elderly onset rheumatoid arthritis with high titer of rheumatoid factor, which was treated with leXunomide, hydroxychloroquine, and lowdose prednisolone. In October 2008, she presented with pain and swelling of the right shoulder which had persisted for 1 month. She had been doing farm work, but denied having experienced any major trauma. Around that time, her arthritis was controlled pretty well. On laboratory test, serum C-reactive protein level was 1.43 mg/dL (normal range, <0.3 mg/dL). Unexpectedly, humeral head was not visible (Fig. 1, short arrow) and soft tissue swelling was present on plain radiograph of the right shoulder. In addition, multiple calciWc materials were found adjacent to the proximal metaphysis of the right humerus (Fig. 1, long arrow). Ultrasonography revealed marked distension of the subacromial bursa and 65 ml of bloody Xuid was aspirated. On Xuid analysis, white blood cell count was 190/mm and red blood cell count 18,000/mm. Because she had been followed up in our rheumatology clinic, we had checked regular chest radiograph in June 2008, 3 months before her right shoulder pain developed. Notably, right humeral head was visible on that chest radiograph (Fig. 2, arrow). Based on the disappeared humeral head and multiple calciWc materials, rapid osteolysis of the humeral head seemed to have occurred during the 3-month period and the vanishing bone disease or Gorham’s disease was diagnosed. Because she was unwilling to undergo further treatment such as shoulder joint arthroplasty, conservative care was done. Vanishing bone disease, called Gorham’s disease, is a rare disease characterized by massive idiopathic osteolysis [1]. It can occur spontaneously or after trauma; however, precise etiology is still not known. In our patient, minor trauma seemed to be the most probable cause based on the hemorrhagic nature of the subacromial bursal Xuid. It was reported that excessive vascular proliferation and increased osteoclastic activity are thought to be the cause of the bone matrix destruction in Gorham’s disease and bone matrix is replaced by thinwalled vessels and Wbrous tissue [2]. Gorham’s disease can involve various bones such as ribs, vertebra, humerus, hip, foot, and even facial bones [3–8]. It can be progressive and spread to adjacent bones. The prognosis varies depending on which bones are involved. In most cases it is rarely fatal, but extension to spinal cord and/or internal organs can be life threatening when vertebra, scapula, rib or sternum are involved. As for the treatment, radiation therapy, chemotherapy, antiresorptive medications, and surgical intervention such as grafting have all been tried with diVerent degrees of success, but eVective therapy is not established yet [1]. So far, only H.-J. Ko · K.-S. Park (&) · C.-S. Cho · H.-Y. Kim Division of Rheumatology, Department of Internal Medicine, Seoul St. Mary’s Hospital, The Catholic University of Korea College of Medicine, 505 Banpo-dong, Seocho-gu, Seoul 137-701, South Korea e-mail: pkyungsu@catholic.ac.kr