Supplementary Material for: Primary Retroperitoneal Filariasis Presenting with Acute Abdomen

Lymphatic filariasis is a common tropical parasitic infection caused by the Nematoda Filarioidae family. Filariasis predominantly affects the lymphoreticular system, leading to lymphedema, elephantiasis, hydrocele, and chyluria. However, its presentation as retroperitoneal cyst is very rare with a reported incidence rate of 1/105,000. We present a rare case of a previously healthy 26-year-old male presenting with abdominal and groin pain associated with chills and vomiting. Computerized tomography scan showed extensive cystic retroperitoneal lesion and ultrasound demonstrated “Dancing Filarial Sign.” Retroperitoneal filariasis can present without peripheral filarial signs. Hence, it should be considered in the differential diagnosis of acute abdominal pain of a patient who is originally from an endemic area.

淋巴丝虫病（Lymphatic filariasis）是一类常见的热带寄生虫感染性疾病，由线虫动物门丝虫科（Nematoda Filarioidae）病原体引发。该病主要累及淋巴网状系统，可导致淋巴水肿、象皮肿、鞘膜积液及乳糜尿等病症。但以腹膜后囊肿为临床表现的病例极为罕见，据报道其发病率为1/105000。本文报告1例罕见病例：患者为既往健康的26岁男性，因畏寒、呕吐伴腹部及腹股沟疼痛就诊。计算机断层扫描（CT）可见广泛的腹膜后囊性病灶，超声检查显示“舞动丝虫征（Dancing Filarial Sign）”。腹膜后丝虫病可无外周丝虫感染相关体征，因此对于原籍为流行区的急性腹痛患者，需将该病纳入鉴别诊断范畴。