Abstract：
Echinococcosis is caused by tapeworms belonging to the Echinococcus genus. The most common site of infection is the liver although it may involve almost any organ. Symptoms of pulmonary echinococcosis vary depending on the location and structure of the cyst. While uncomplicated cysts usually appear at imaging as well-defined homogeneous lesions with fluid content and smooth walls of variable thickness, complicated lesions may have a more heterogeneous content with higher density making more difficult the distinction from malignancies or other infections. Hereby we describe the case of a 61-year-old Northern African male admitted to our tertiary center for left upper chest pain who then underwent a chest computed tomography (CT) scan which demonstrated a large hypodense lesion, with smooth and thick walls, in the upper left lobe. The following magnetic resonance confirmed the homogeneous fluid content, and the 18 F- fluorodeoxyglucose-positron emission tomography/CT demonstrated a mild uptake of the walls. According to these findings, the main differential diagnoses at imaging included bronchogenic cyst, synovial sarcoma, and pulmonary hematoma although the patient denied any recent trauma. Given the large size and clinical symptoms he underwent surgery. Intra-operative frozen section, supported by imprint cytology, excluded the presence of malignancy while suggested an echinococcal laminar exocyst. The final pathological examination confirmed the diagnosis of echinococcosis (i.e., Echinococcus Granulosus protoscolex). After surgery he was treated with albendazole and at the six-month follow-up he was in good clinical conditions. Our case highlights the importance of considering rare infections, particularly in individuals from endemic areas. Frozen tissue analyses can be a diagnostic challenge and often require ancillary tools such as imprint cytology and serial sections for more sensitive and accurate diagnosis.
摘要：
棘球蚴病是由棘球蚴属的tape虫引起的。最常见的感染部位是肝脏，尽管它可能涉及几乎任何器官。肺包虫病的症状取决于囊肿的位置和结构。虽然不复杂的囊肿通常在成像时表现为明确的均质病变，具有液体含量和厚度可变的光滑壁，复杂的病变可能具有更多的异质性，密度更高，使得与恶性肿瘤或其他感染的区分更加困难。在此，我们描述了一名61岁的北非男性因左上胸痛进入我们的三级中心的病例，然后进行了胸部计算机断层扫描（CT）扫描，显示出较大的低密度病变，墙壁光滑厚实，在左上叶。以下磁共振证实了均匀的流体含量，18F-氟脱氧葡萄糖-正电子发射断层扫描/CT显示壁的轻度摄取。根据这些发现,影像学的主要鉴别诊断包括支气管囊肿，滑膜肉瘤,和肺血肿，尽管患者否认近期有任何创伤。鉴于大尺寸和临床症状，他接受了手术。术中冰冻切片,由印记细胞学支持，排除恶性肿瘤的存在，同时提示有棘球蚴层状外囊。最终的病理检查证实了包虫病的诊断（即，细粒棘球蚴）。手术后，他接受了阿苯达唑治疗，在六个月的随访中，他的临床状况良好。我们的案例突出了考虑罕见感染的重要性，特别是来自流行地区的个人。冷冻组织分析可能是诊断挑战，并且通常需要辅助工具，例如印迹细胞学和连续切片，以实现更灵敏和准确的诊断。
