易感染性疾患既往のない患者に発症した稀な化膿性大胸筋炎の2例

Successful Conservatively Treatment of Pectoralis Major Pyomyositis in Immunocompetent Patients. Report of Two Cases

　われわれは易感染性疾患の既往のない患者に発症した化膿性大胸筋炎の2例を経験した．症例1は78歳の男性で，主訴は発熱であった．自発痛はないが左前胸部の軽度腫脹，発赤を認めた．症例2は29歳の女性で，主訴は発熱，後頚部・右上肢痛，右手のしびれであった．2例とも発症翌日に，胸部CT，MRIで化膿性大胸筋炎と診断され，抗菌薬投与で保存的に治癒した．化膿性大胸筋炎は本邦では非常に稀であり，診断が遅れることがある．過去の報告では手術を要した症例が多かったが，早期に診断，治療を行えば保存的に治癒する可能性があると考えられる．

　We report two cases of pectoralis major pyomyositis in immunocompetent patients.　The patient in Case 1 was a 78-year-old man who had a high fever.　Slight left precordial swelling and redness were observed, but the patient did not have pain.　The patient in Case 2 was a 29-year-old woman who had a high fever, posterior neck pain, right upper limb pain, and numbness of the right hand.　A diagnosis of pectoralis major pyomyositis was made in both cases based on the CT and MRI findings on the day after the onset of their symptoms, and they were treated conservatively with antibiotics.　Since pectoralis major pyomyositis currently is very rare in Japan, early, accurate diagnosis is sometimes difficult.　Although most previous reports have described the need for surgical treatment, our experience in these two cases suggests that early diagnosis enables patients to be cured by conservative treatment without surgery.