背景：jirovecii肺孢子虫感染是人类免疫缺陷病毒（HIV）感染患者中最常见的机会性感染；然而，使用抗逆转录病毒治疗后，肺外P.jirovecii感染极为罕见。这里,我们报告了一例晚期HIV感染患者中的第二例由P.jirovecii感染引起的椎旁肿块。
方法：一名45岁女性在劳累时出现呼吸困难，在前4个月内体重明显下降。最初的全血细胞计数（CBC）发现显示全血细胞减少，血红蛋白（Hb）水平为8.9g/dL，白细胞（WBC）计数为2180细胞/mm3，中性粒细胞为68％，和106,000个细胞/mm3的血小板计数。抗HIV阳性,具有16个细胞/mm3的绝对分化簇4(CD4)计数。胸部计算机断层扫描显示，右椎旁区域（T5-T10水平）的软组织肿块样病变增强，左下肺的厚壁腔病变增强。进行了CT引导下的椎旁肿块活检，组织病理学显示肉芽肿性炎症由上皮样细胞和巨噬细胞的致密聚集体组成，肉芽肿性炎症中散落的粉红色泡沫状至颗粒状物质的病灶。Gomori亚甲基胺银（GMS）染色显示出薄薄的囊状结构（空丝），观察到在形态上与P.jirovecii一致。来自椎旁质量的分子鉴定和DNA测序与P.Jirovecii100%相同。患者成功治疗口服甲氧苄啶-磺胺甲恶唑3周和抗逆转录病毒治疗（ART）替诺福韦（TDF），拉米夫定(3TC),和dolutegravir（DTG）。治疗后2个月的胸部CT随访显示，椎旁肿块和空洞性肺病变的大小均减小。
结论：肺外肺孢子菌病（EPCP）在广泛使用ART后已成为HIV感染患者中极为罕见的疾病。在怀疑患有或诊断为肺孢子虫肺炎并表现出非典型症状和/或体征的未经ART治疗的HIV感染患者中，应考虑使用EPCP。对受累组织进行GMS染色的组织病理学检查对于诊断EPCP是必要的。
BACKGROUND: Pneumocystis jirovecii infection is the most common opportunistic infection that causes pneumonia in human immunodeficiency virus (HIV)-infected patients; however, extrapulmonary P. jirovecii infection is extremely rare after the use of antiretroviral therapy. Here, we present the second reported case of paraspinal mass caused by P. jirovecii infection in an advanced HIV-infected patient.
METHODS: A 45-year-old woman presented with dyspnea on exertion, and significant weight loss within the preceding 4 months. Initial complete blood count (CBC) findings revealed pancytopenia with a hemoglobin (Hb) level of 8.9 g/dL, a white blood cell (WBC) count of 2180 cells/mm3 with 68% neutrophils, and a platelet count of 106,000 cells/mm3. Anti-HIV was positive with an absolute cluster of differentiation 4 (CD4) count of 16 cells/ mm3. A computed tomography scan of the chest revealed an enhancing soft tissue mass-like lesion at the right paravertebral region (T5-T10 level) and a thick-walled cavity lesion at the left lower lung. A CT-guided biopsy of the paravertebral mass was performed and histopathology revealed granulomatous inflammation consisting of dense aggregates of epithelioid cells and macrophages, and scattered foci of pink foamy to granular materials amidst the granulomatous inflammation. Gomori methenamine silver (GMS) staining revealed thin cystic-like structures (ascus) that were observed to be morphologically consistent with P. jirovecii. Molecular identification and DNA sequencing from the paraspinal mass was 100% identical to P. Jirovecii. The patient was successfully treated with oral trimethoprim-sulfamethoxazole for 3 weeks and antiretroviral therapy (ART) with tenofovir (TDF), lamivudine (3TC), and dolutegravir (DTG). A follow-up CT scan of the chest at 2 months after treatment showed a decrease in sizes of both the paravertebral mass and the cavitary lung lesion.
CONCLUSIONS: Extrapulmonary pneumocystosis (EPCP) has become an extremely rare condition in HIV-infected patients after the widespread use of ART. EPCP should be considered in ART-naive HIV-infected patients suspected of having or diagnosed with Pneumocystis jirovecii pneumonia who present with atypical symptoms and/or signs. Histopathologic examination with GMS staining of affected tissue is necessary for the diagnosis of EPCP.
