巨大な滑液嚢腫を合併した腱板断裂の1例

Giant Synovial Cyst Occurred in a Patient with Rotator Cuff Tear. Case Report

　巨大な滑液嚢腫に合併した腱板断裂の1例を経験した．症例は69歳，女性．主訴は右肩腫脹，疼痛で，特に誘因なく右肩関節痛が出現し腫脹を認めたため当科を初診した．初診時，右三角筋前面部に腫瘤を触知し，MRI画像で三角筋下前面にT1強調像で低信号，T2強調像で低～高信号が混在した腫瘤を認め，棘上筋腱の不連続性も確認された．腫瘤の切除および棘上筋腱の再建を一期的に施行した．術後，腫瘤の局所再発はない．本症例では，腱板断裂によるvalvular mechanismに加え，滑膜の慢性炎症が嚢腫形成を助長したと考えられた．

　We report a patient with a giant synovial cyst complicated with a rotator cuff tear. A 69-year-old woman with swelling and pain in the right shoulder without a special history was found to have swelling palpated in the anterior region of the right deltoid muscle. T1-and T2-weighted MR imaging showed low signal intensity and low to high signal intensities in the inferior anterior region of the deltoid muscle, suggesting a synovial cyst. Imaging also showed a full thickness tear of the supraspinous tendon. Resection of the giant synovial cyst and reconstruction of the supraspinous tendon were done in one-stage surgery. No local recurrence has been seen. In this patient, in addition to the valvular mechanism related to the full thickness rotator cuff tear, chronic inflammation of the synovial membrane may have contributed to formation of the synovial cyst.