孤発性と考えられる進行性化骨性筋炎の1例

抄録

We report a case of myositis ossificans progressiva in Japan. The patient was 7 yearsold who had swelling and pain of his back and arms. He had surgically treated for halluces valgus of his left foot when he was 2 years old. Laboratory examination on admission of our hospital showed elevated serum phosphate and calcium. On plain roentogenogram, ectopic ossification of bilateral biceps muscles was noted. Chest computed tomography showed severe deformity and constriction of his thorax, and the ectopic ossification was confirmed. Magnetic resonance imaging of his back and neck revealed massive swelling of his muscles including left sternocleidomastoid muscle. Muscle biopsy has not been performed, because his diagnosis of having myositis ossificans progressiva is definitive, and histological examination of the specimen has been reported to have difficulty on differential diagnosis of myositis ossif icans progressiva from other types of malignancies of muscle origin including soft tissue sarcoma and inflammatory myositis. In addition, muscle injury caused by the biposy procedure accelerates progression of the disease including inflammation and ossification. There is no clear cut explanation of the pathophysiology of nor effective treatment of the disease. We need to accumulate and experience more patients with the same disease to elucidate their pathophysiology and to carry out the genetic linkage study of this disease in Japan.