Foley N M, Griffiths M H, Miller R F
Department of Medicine, University College London Medical School, Middlesex Hospital.
Thorax. 1993 Oct;48(10):996-1001. doi: 10.1136/thx.48.10.996.
Infection with Pneumocystis carinii typically results in a pneumonia which histologically is seen to consist of an eosinophilic foamy alveolar exudate associated with a mild plasma cell interstitial infiltrate. Special stains show that cysts of P carinii lie within the alveolar exudate. Atypical histological appearances may occasionally be seen, including a granulomatous pneumonia and diffuse alveolar damage. In these patients the clinical presentation may be atypical and results of investigations negative unless lung biopsies are performed and tissue obtained for histological examination.
The incidence and mode of presentation of histologically atypical pneumocystis pneumonia was studied in a cohort of HIV-I antibody positive patients.
Over a 30 month period 138 patients had pneumocystis pneumonia, of whom eight (6%) had atypical histological appearances which were diagnosed (after negative bronchoalveolar lavage) by open lung biopsy in five, percutaneous biopsy in one, and at post mortem examination in two. Atypical appearances included granulomatous inflammation in four patients, "pneumocystoma" in two (one also had extrapulmonary pneumocystosis), bronchiolitis obliterans organising pneumonia in one patient, diffuse alveolar damage and subpleural cysts in one (who also had intrapulmonary cytomegalovirus infection), and extrapulmonary pneumocystosis in two patients.
Various atypical histological appearances may be seen in pneumocystis pneumonia. Lung biopsy (either percutaneous or open) should be considered when bronchoalveolar lavage is repeatedly negative and evidence of P carinii should be sought, by use of special stains, in all lung biopsy material from HIV-I antibody positive patients.
卡氏肺孢子虫感染通常导致肺炎，组织学上可见由嗜酸性泡沫状肺泡渗出物及轻度浆细胞间质浸润组成。特殊染色显示卡氏肺孢子虫囊肿位于肺泡渗出物内。偶尔可见非典型组织学表现，包括肉芽肿性肺炎和弥漫性肺泡损伤。在这些患者中，临床表现可能不典型，除非进行肺活检并获取组织进行组织学检查，否则检查结果可能为阴性。
在一组HIV-1抗体阳性患者中研究组织学非典型肺孢子虫肺炎的发病率和表现方式。
在30个月期间，138例患者患有肺孢子虫肺炎，其中8例（6%）有非典型组织学表现，5例通过开胸肺活检确诊（支气管肺泡灌洗结果为阴性后），1例通过经皮活检确诊；2例在尸检时确诊。非典型表现包括4例患者出现肉芽肿性炎症，2例出现“肺孢子虫瘤”（其中1例还伴有肺外肺孢子虫病），1例患者出现闭塞性细支气管炎机化性肺炎，1例出现弥漫性肺泡损伤和胸膜下囊肿（该患者还伴有肺内巨细胞病毒感染），2例患者出现肺外肺孢子虫病。
肺孢子虫肺炎可见多种非典型组织学表现。当支气管肺泡灌洗多次为阴性且应寻找卡氏肺孢子虫证据时，应考虑进行肺活检（经皮或开胸），并对所有HIV-1抗体阳性患者的肺活检材料使用特殊染色法进行检查。
