限局性浸潤影を呈した原発性肺アミロイドーシスの2例

Primary Pulmonary Amyloidosis with a Localized Consolidation：Report of Two Cases

はじめに　アミロイドーシスは，折り畳み異常を起こした前駆蛋白質が特有のβシート構造に富むアミロイド線維を形成し，全身のさまざまな臓器に沈着することで機能障害を起こす疾患の総称である．アミロイドーシスは，複数の臓器にアミロイドが沈着する全身性と，特定の臓器に限局して沈着する限局性に分類される．原発性肺アミロイドーシスは，アミロイド沈着が気道系に限局しているものとされているが1），限局性浸潤影を呈する原発性肺アミロイドーシスはまれであり，報告する．

We experienced two cases of primary pulmonary amyloidosis with a localized consolidation. Case 1 is a 80-year-old man, who was found to have an abnormal chest nodular shadow with blurred margin at a medical examination. Chest computed tomography （CT） showed a localized consolidation on the periphery of the upper lobe of the right lung. A CT-guided biopsy was performed. Case 2 is a 66-year-old woman, who was found to have an abnormal chest opacity at a medical examination. Chest CT showed a localized gathering of small nodules in the right lower lobe. Gradual enlargement was noted by follow up CT and the accumulation of fluorodeoxyglucose （FDG） was shown by PET/CT. In consideration of primary lung cancer or malignant lymphoma, right lower lobectomy was performed. Both cases were pathologically diagnosed as pulmonary amyloidosis. Since no findings of amyloid deposits in other organs or of existence of any blood disorders, a diagnosis of primary pulmonary amyloidosis was made.