慢性嗜伊紅性白血球肺炎CEP(Chronic eosinophilic pneumonia) 是一種極為罕見的肺部疾 病。周邊血液中有大於6% 的嗜伊紅性白血球以及肺泡灌洗液中BAL (Bronchoaveolar lavage) 有超過25% 的嗜伊紅性白血球為診斷CEP 的要點，診斷上的確立通常並不需要病理的切片。 臨床上需要排除一些相類似性的疾病( 如藥物的使用情況、化學物質、過敏原的暴露) 及和 其他的肺部疾病( 間質性肺疾病、感染性疾病)。它的病徵進展是很緩慢且很輕微，所以從症 狀的開始到診斷的時候通常都已經經過4 到6 個月了。本文案例為一35 歲的年輕女性，因健 康檢查胸部X 光片異常被通報為肺結核而來胸腔科就診。爾後因為70% 的嗜伊紅性白血球血 症以及肺泡灌洗液出現49% 的嗜伊紅性白血球被改診斷為慢性嗜伊紅性白血球肺炎。

Chronic eosinophilic pneumonia (CEP) is an uncommon pulmonary disease. The key diagnostic criteria for CEP are 1) over 6% of eosinophils in peripheral blood, and 2) more than 25% of eosinophils in bronchoalveolar lavage. Lung biopsy is not a necessary diagnostic criterion for CEP. In clinical practice, similar symptoms such as drug-related interactions and exposure to chemical molecules or allergens, and other pulmonary diseases such as interstitial/ infectious lung disease, should be ruled out. CEP has a gradual onset with minor symptomatic effects on patients, therefore it will often take approximately four to six months from initial discovery of symptoms to confirmed diagnosis. This is the case of a 35-year-old female who were initially diagnosed as pulmonary tuberculosis due to abnormal chest X-ray, but was later found to have 70% eosniophil in peripheral blood and 49% eosinophil in bronchoalvelor lavage fluid with confirmed diagnosis of CEP. (J Intern Med Taiwan 2016; 27: 333-337)