Recurrent Inactive Hydatid Cyst of the Liver Causing Restrictive Pulmonary Physiology

Hydatid and alveolar cysts are formed by the helminths Echinococcus granulosus and Echinococcus multilocularis, respectively, which are endemic to pastoral areas, and are more commonly found in South America, the Mediterranean, Russia, and China. Hydatid cysts can cause bacteremia, form abscesses, or cause mass effect by compressing surrounding organs. Strategies to prevent such complications include benzimidazoles, surgical resection, and Puncture, Aspiration, Injection and Re-aspiration (PAIR) procedure. A 71-year-old Egyptian man with remote history of Echinococcus infection one year status post PAIR procedure, presented with dyspnea on exertion. On exam, the patient had a palpable right upper quadrant mass. The patient had a known small hydatid liver cyst on prior ultrasound, however repeat imaging showed growth to 15×19×14cm, with right hemidiaphragm elevation, compressive atelectasis, and compression of the right atrium. He had no peripheral eosinophilia and negative echinococcal serology, consistent with remote infection. The patient underwent repeat PAIR procedure and 3L of serous fluid was drained from the cyst. Fluid analysis was negative for scolices, cysts or hooklets. His symptoms improved; however the cyst re-accumulated 1 month later. Total cystectomy was performed surgically by hepatic wedge resection, with permanent improvement in symptoms. This case is a rare example of Echinococcus infection causing significant respiratory morbidity requiring repeated invasive procedures and surgery, in the setting of inactive disease.