画像所見で大腿骨骨腫瘍と診断されたSAPHO症候群の3例

SAPHO Syndrome Simulating Bone Tumors on the Femur. Report of Three Cases

　大腿骨骨腫瘍との鑑別を要したSAPHO症候群の3例を経験した．性別は全例女性であり，主訴は大腿部痛であった．全例とも特に誘因なく大腿部痛を自覚し，X線撮影で異常所見が認められ，骨腫瘍を疑い当科を紹介され受診した．2例に掌蹠膿疱症の治療歴を認めた．単純X線所見では大腿骨骨幹部に骨皮質の肥厚と不整像を認めた．MRIでは骨皮質の肥厚と骨髄の不整な信号強度変化，および骨皮質周囲組織のびまん性な高輝度変化が見られた．全例非ステロイド性抗炎症薬の服用により症状は軽快した．本疾患の診断には，合併する骨炎の病態を認識することや，MRIにおける骨髄と骨皮質周囲組織の炎症，およびそれに伴う浮腫の存在が重要である．

　Three patients, all women, who complained of continuous pain in the thigh in the absence of trauma were referred to our hospital because a bone tumor was suspected.　Two of the patients had a history of pustulosis palmaris et plantaris.　A standard roentgenogram showed cortical thickening and irregularity of the mid-shaft of the femur.　Subsequent MRI revealed an inflammatory reaction in the bone marrow and around the cortical thickening.　The symptoms were relieved by NSAID therapy.　When a patient presents with cortical thickening and irregularity of a tubular bone, especially in the presence of pustulosis palmaris et plantaris, the possibility of the osteitis of the SAPHO syndrome should be considered.　MRI may be helpful in making a definitive diagnosis.