Musculoskeletal Ultrasound Manifestation of Osteoarthropathy in EMO Syndrome.

EMO syndrome is a rare condition seen in ＜1% of patients with Graves' disease. It is defined as a triad of exophthalmos, pretibial myxedema, and osteoarthropathy (1,2). We herein report a case of EMO syndrome in which musculoskeletal ultrasound (MSUS) was useful for the diagnosis of osteoarthropathy. A 54-year-old woman had a 1-year history of hand stiffness. She had been diagnosed with ophthalmopathy associated with Graves' disease 6 years earlier (TSAb 3,674% TRAb 32.9 IU/L). A physical examination revealed clubbed fingers and pretibial non-pitting edema. X-ray showed brushed periosteal hypertrophy on the metacarpal and metatarsal bones (Picture 1, 2). MSUS showed irregular bone prominence (Picture 3, 4) and local subcutaneous hypertrophy of the left lower leg, which was proven to be myxedema by a histopathologic examination. It is not easy to detect periosteal hypertrophy on X-ray. Since MSUS has a high spatial resolution and little direction dependence, periosteal hypertrophy can be easily detected using this modality.

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The authors state that they have no Conflict of Interest (COI).