進行胃癌から腫瘍性血栓性肺微小血管症による亜急性肺高血圧を呈し急性の経過で死亡した1例

Subacute Pulmonary Hypertension due to Pulmonary Tumor Thrombotic Microangiopathy from Gastric Cancer：a case report

要旨　45歳，男性．急激な呼吸困難を主訴に来院．血圧低下，低酸素状態，心電図で右心負荷所見，心エコーで右室の拡大と心室中隔の扁平化を認めた．肺塞栓症を疑い胸部造影CT，肺動脈造影を施行したが重症肺高血圧症を認めるものの血栓像は認めなかった．肺血流シンチでは斑状の陰影欠損から多発性肺塞栓症の所見であった．薬物治療に抵抗性で，病状は進行し第2病日に心肺停止となり蘇生術を行った．自己心拍は再開し大動脈バルーンポンプ，経皮的心肺補助装置で一時的に血行動態を保ったが，蘇生後脳症と肺高血圧の進行から第3病日に死亡した．剖検所見で多臓器転移を伴うIV型の進行胃癌を認め，肺病変は腫瘍性血栓性肺微小血管症(pulmonary tumor thrombotic microangiopathy：PTTM)による肺高血圧症と診断された．PTTMは生前診断，治療とも困難で，極めて予後不良の疾患である．

Summary

　A 45-year-old man with acute progressive dyspnea was admitted to our hospital. His consciousness was clear, but he was hypotensive. ECG and an echocardiogram demonstrated right ventricular overload and pulmonary hypertension, so a diagnosis of acute pulmonary embolisms was considered. Chest computed tomography and pulmonary angiography showed no evidence of the thrombus. However, catheterization revealed severe pulmonary hypertension(systolic pulmonary artery pressure80～90mmHg). Pulmonary perfusion scintigraphy demonstrated diffuse perfusion defect, consistent with multiple pulmonary microembolisms. The pulmonary hypertension resisted all medical treatment and was progressive. On the second hospital day, the patient suffered cardiac arrest and cardiopulmonary resuscitation was initially successful. Hemodynamic stability was temporally maintained using intra-aortic ballon pumping and percutaneous cardio-pulmonary support. However, because hypoxic brain damage was severe and pulmonary hypertension was progressive, the patient died on the third hospital day. Autopsy revealed type IV progressive gastric cancer with multiple metastasis, and pulmonary tumor thrombotic microangiopathy(PTTM) from the gastric cancer. The direct cause of death was pulmonary hypertension secondary to PTTM. PTTM is a difficult antemortem diagnosis to make and carries a very poor prognosis.