C3-04 An Unexpected Case of Isolated Pulmonary Echinococcus

Introduction

Lung cysts are uncommon in children with a broad differential. This case highlights a unique presentation of pulmonary Echinococcus in the United States.

Case

A 5-year-old previously healthy male presented to the ED with persistent right-sided chest pain after a fall 9 months prior. He was afebrile, without respiratory distress or hypoxia and with unremarkable lung exam. Chest imaging was obtained, with x-ray and subsequent CT notable for large, bilateral fluid-filled spherical cysts measuring 6.7 and 6.9 cm respectively, similar in size to a tennis ball, comprising approximately 1/3 to 1/2 of each lung field (Image 1). Laboratory workup was notable for an elevated ESR of 35 (0-20). He was discharged home with referral to pulmonary clinic. Prior to clinic follow up 4 weeks later, he returned to the ED with ongoing chest pain, and now cough, dyspnea and fever to 102 F. Repeat x-ray was significant for interval drainage of the left lung lesion. He was discharged with Augmentin which he was still completing at the time of his clinic visit. Clinic history was notable for no recurrent respiratory illnesses/symptoms prior to this presentation. Travel history included Europe and the Middle East. Our differential diagnosis included infection, congenital pulmonary lesions, traumatic lung cysts, and malignancy. The chronicity, cyst size and bilateral nature made bacterial/viral infections and congenital lesions unlikely. The spontaneous cyst drainage raised concern for parasitic infection and further imaging was obtained to evaluate for hepatic (or extrapulmonary) cysts. A “water lily sign” was seen in the left cyst, suggesting inner cyst rupture. Interestingly, there was no intra-abdominal, hepatic or pelvic disease noted. Labs demonstrated a new eosinophilia (8.6%) and elevated ESR 46 (0-10). Despite the lack of hepatic cysts, these findings were concerning for parasitic infection and an Echinococcus antibody IgG and western blot was sent, returning positive. The patient underwent removal of the right lung cyst with pathology confirming the diagnosis of Echinococcus lung infection.

Discussion

This case represents a unique presentation of cystic Echinococcosis with isolated pulmonary disease. Single organ involvement is commonly identified in the liver, with isolated pulmonary infections reported in only 10-30% of cases. This diagnosis should be considered in patients presenting with cystic lesions in the chest or abdomen, particularly when history is not consistent with acute infection or congenital lesion. While Echinococcus is not endemic to the US, it remains an important consideration in patients presenting with cystic lung lesions.

This abstract is funded by: None