肋骨発生動脈瘤様骨囊腫の1例

Aneurysmal Bone Cyst of the Rib：Report of a Case

はじめに　動脈瘤様骨囊腫は良性の腫瘍類似疾患で，通常は長管骨骨幹部，脊椎での発生が多く，肋骨発生はまれである．われわれは，疼痛により発見された肋骨発生動脈瘤様骨囊腫の1例を経験したので報告する．

We report a case of an aneurysmal bone cyst （ABC） originating in a rib. A 34-year-old woman was admitted to our medical department for evaluation of left rib pain and an abnormal shadow in the left 7th rib observed on chest radiography. Computed tomography （CT） revealed an osteolytic lesion involving the left 7th rib. Positron emission tomography/CT showed slight fluorodeoxyglucose uptake in the lesion. We performed 7th rib resection with a 4 cm margin from the tumor, including the intercostal muscles in the 6th and 7th interspaces. Histopathological examination of the resected specimen showed multiple blood-filled spaces and fibrous trabeculae, which confirmed the diagnosis of an ABC. The patient’s postoperative course was uneventful. Although rare, clinicians should consider ABCs in the differential diagnosis of rib tumors.