Popliteal Echinococcosis: A Long Journey from the Liver

Intra-abdominal and pelvic seeding of hepatic cystic echinococcosis to various organs is a known feature of the disease. Dissemination into distal extremities is uncommon and in this report, we present a case of disseminated cystic echinococcosis extending toward the right popliteal fossa.

A 68-year-old male presented with swelling in the right upper leg and discomfort in the right popliteal region. Work-up revealed various cystic mass lesions of different sizes within the liver, intra-abdominal cavity, right inguinal region, right femoral region, and right popliteal fossa. Diagnosis of hepatic cystic echinococcosis was made and the patient was started on medical therapy.

Hepatic cysts can be easily observed with ultrasonography and the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) classification system is commonly used to further classify cysts. The work-up of the disseminated disease involves further radiological modalities such as computerized tomography and magnetic resonance imaging. Management includes medical therapy, percutaneous drainage, or surgery depending on hepatic cyst localization and the presence of dissemination.

Extrahepatic dissemination of cystic echinococcosis is commonly encountered in endemic areas. Rarely, hepatic cysts can spread beyond the abdomen towards the distal extremities. Therefore, cystic echinococcosis should be included in the differential diagnosis in endemic areas where patients present with cystic masses.