下大静脈への右部分肺静脈還流異常症（Scimitar症候群の不完全型）の2例

Two cases of anomalous pulmonary venous return into inferior vena cava (Scimitar syndrome)

　Scmitar症候群は1960年Neilにより命名された稀な疾患で，「右肺静脈の大静脈への異常還流」「右肺形成不全」「心臓の右方転位」を三徴とする。現在までに世界で130例あまり，日本で26例が報告されているにすぎない。本症は胸部単純X線写真上，心陰影右縁近くで右下肺野に三日月刀状の異常陰影（Scimitar sign）を呈し，注意深い読影により診断が可能である。われわれは胸部単純X線写真上Scimitar signを呈し，肺血管造影および右心カテーテル法によりScimitar　症候群と診断しえた2症例を経験したので報告する。

Case 1 : A 33 year-old man was admitted for the evaluation of abnormal chest X-ray film, reveal-ing a shadow near the right heart border pathognomonic of Scimitar syndrome. Angiograph-ic studies showed a pulmonary vein draining into the inferior vena cava. Dextroposition of the heart and hypoplasia of the right lung were not confirm-ed. Case 2: A 26 year-old-man was admitted for the evaluation of abnormal chest X-ray film, revealing the Scimitar vein near the right heart border. Angiographic studies showed an anomalous inferior vena caval drainage of the right pulmonary vein. The heart was slightly deviated to the right and vital capacity was decreased on pulmonary function test.

Scimitar syndrome is an anomalous pulmonary venous drainage to the inferior vena cava, often associated with the rightward deviation of the heart and hypoplasia of the right lung. In our two cases anomalous of the right lung and dextroposition of the heart were not so marked. It should be noted that Scimitar syndrome is able to be diagnosed only by a plain chest X-ray film.