多発性骨髄腫治療中に発症した肺静脈閉塞症(PVOD)の1剖検例

An Autopsy Case of Pulmonary Veno-occulusive Disease(PVOD)with Multiple Myeloma

要旨

　患者は多発性骨髄腫治療中の67歳，女性．MP療法でM蛋白は順調に減少した．その後M蛋白の増加は認めなかったが，労作時呼吸困難が出現するようになり次第に増悪した．肺動脈カテーテル検査で著明な肺高血圧が認められ，酸素投与や血管拡張剤，抗凝固剤，利尿剤投与などを行い病状は徐々に安定化したが，突然強い呼吸困難を訴えた直後死亡した．肺の剖検所見では小葉間静脈以下の小ないし細小静脈が内膜の浮腫および線維性肥厚，中膜の線維化・平滑筋の増生で狭窄・閉塞しており，リンパ管や肺胞毛細血管の拡張・増生が認められた．以上より本症例は肺静脈閉塞症(PVOD)と診断した．PVODは肺高血圧症のなかでは非常に稀な病態であり，病因や治療法も現在のところ明らかになっていない．本症例はPVOD発症以前から臨床経過を観察しえた貴重な症例と考え，報告する．

Summary

　A 67-year-old woman was admitted to our hospital with complaints of increasing dyspnea. The patient was diagnosed as having multiple myeloma about ten years ago, and she had been administered melphalan and predonisolone(MP-therapy) from 1995 to 1998. Consequently, M-proteinemia was significantly improved. However, dyspnea in the course of exertion developed after MP-therapy and the patient's condition gradually grew worse. Therefore, she was admitted into our hospital in 2000. Although she received medication, she didn't respond and died suddenly five months later.

　At the postmortem examination of the lung, we observed the extensive and diffuse occlusion of pulmonary veins by intimal thickening due to edematous or fibrous tissue and by an increase of smooth muscles of the media. The intimal thickening involved venules and small vein lobular septa. Alveolar capillaries and became so engorged and tortuous as to resemble pulmonary capillary hemangiomatosis. Lymphatics were dilated, too. Pulmonary arterioles exhibited moderate medial hypertrophy and arteritis and plexiform lesions were absent. Fresh thrombus and lung fibrosis were not detected. Accordingly,we concluded that pulmonary hypertension resulted from pulmonary veno-occulusive disease.