Barth Thomas F E, Reinehr Michael, Frey Hanspeter, Weber Achim
Institut für Pathologie, Universität Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Deutschland.
Institut für Pathologie, Hegau-Bodensee-Klinikum, Singen, Deutschland.
Pathologie (Heidelb). 2025 Aug 6. doi: 10.1007/s00292-025-01461-7.
Alveolar and cystic echinococcosis are rare zoonotic diseases caused by the larval stages of E. multilocularis and E. granulosus. Due to their tumour-like growth, it is often necessary to differentiate them from neoplasms of the liver both macroscopically and histologically. The larval stage is localized predominantly, but not exclusively, in the liver and is characterized for Echinococcus multilocularis macroscopically by a necrotic, "bread-like" ill-defined lesion with intermingled microcysts; in contrast, lesions of E. granulosus show well-defined "noodle- and grape-like" macrocystic lesions. Histologically, the lesions of E. multilocularis are characterized by a tubular, infiltrative growth accompanied by extensive necrosis and a rim composed of epithelioid cells, a fibrotic zone, and a lymphoplasmacytic infiltrate at the transition to non-infected liver tissue. In E. granulosus the necrotic area is less pronounced, without tubular growth and is followed by a rim area identical to lesions caused by E. multilocularis, with the fibrosis zone being significantly wider. The identification of the strongly PAS-positive fragmented lamellar body in the necrotic area is essential. This structure is narrow and fragmented in the larval stage of E. multilocularis, whereas it is distinctly wider in E. granulosus. The positive immunohistochemical staining with monoclonal antibody (mAb) EmG3 confirms the diagnosis of echinococcosis. Regarding the differential diagnosis by immunohistochemistry, the laminated layer of E. multilocularis stains positive with the monoclonal antibodies (mAb) EmG3 and Em2G11, whereas the laminated layer of E. granulosus sensu is only positive with mAb EmG3. Immunohistochemically, fragments of the lamellar body can be detected in the germinal centres of draining lymph nodes infections caused by E. multilocularis and E. granulosus (small particles of E. multilocularis, SPEMs; and small particles of E. granulosus, SPEGs), thus allowing the diagnosis even on small biopsies without lamellar body.
肺泡型和囊型棘球蚴病是由多房棘球绦虫和细粒棘球绦虫的幼虫阶段引起的罕见人畜共患病。由于它们呈肿瘤样生长，通常需要在宏观和组织学上与肝脏肿瘤进行鉴别。幼虫阶段主要（但并非仅）定位于肝脏，多房棘球绦虫幼虫阶段在宏观上的特征是坏死的、边界不清的“面包样”病变，伴有微囊肿；相比之下，细粒棘球绦虫的病变表现为边界清晰的“面条样”和“葡萄样”大囊型病变。组织学上，多房棘球绦虫的病变特征为管状浸润性生长，伴有广泛坏死，在与未感染肝脏组织交界处有一层由上皮样细胞、纤维化带和淋巴细胞浆细胞浸润组成的边缘。细粒棘球绦虫的坏死区域不那么明显，无管状生长，随后是与多房棘球绦虫引起的病变相同的边缘区域，纤维化带明显更宽。在坏死区域鉴定出强PAS阳性的碎片状板层体至关重要。该结构在多房棘球绦虫幼虫阶段狭窄且呈碎片状，而在细粒棘球绦虫中明显更宽。用单克隆抗体（mAb）EmG3进行免疫组化阳性染色可确诊棘球蚴病。关于免疫组化鉴别诊断，多房棘球绦虫的板层层用单克隆抗体（mAb）EmG3和Em2G11染色呈阳性，而狭义细粒棘球绦虫的板层层仅用mAb EmG3呈阳性。免疫组化方面，在多房棘球绦虫和细粒棘球绦虫引起的引流淋巴结感染的生发中心可检测到板层体碎片（多房棘球绦虫小颗粒，SPEMs；细粒棘球绦虫小颗粒，SPEGs），因此即使在没有板层体的小活检标本上也能做出诊断。
