A 68-year-old Algerian man, resident in the Paris area for more than 40 years, but regularly traveling in his country of origin, was incidentally found to have a heterogeneous splenomegaly (195 × 105 × 150 mm) on an abdominal computed tomography ordered for an aortic aneurysm. He was asymptomatic. The spleen contained a large lesion with small calcifications (Figure 1). T2-weighted magnetic resonance imaging (MRI) confirmed the presence of a 9-cm-large splenic lesion with a hypointense rim and numerous intraluminal cysts (Figure 2). Physical examination revealed a splenomegaly. Routine blood test results were unremarkable. Blood eosinophilia was 500/mm3 (N≤ 500/mm3).
What is the origin of these cysts?
These magnetic resonance images of splenic cysts are characteristic of cystic echinococcosis (hydatid disease). However, World Health Organization radiological classification is based on ultrasound images.1,2 No other organic cyst was found on total body tomodensitometry. The primary sites of hydatid cysts are the liver and lungs (70 and 20%, respectively). Prevalence of spleen localization is about 2.5% in endemic area.3 The origin of the patient raised in an endemic area strengthens the suspected diagnosis of this neglected disease, though he did not recall close contact with sheep or dogs. Humans usually become infected during childhood mainly after direct contact with dogs fed with the viscera of home-butchered sheep or ingestion of contaminated food.2,4 Hydatid serologies (Echinococcus granulosus antigen) were positive with titers of 200 U for ELISA (threshold 35) and 2560 for hemagglutination (threshold 160), respectively. Undetectable immune response as well as normal eosinophil count do not eliminate diagnosis.5 The patient underwent surgical cyst (Figure 3) and spleen (Figure 4) excision after more than one recommended week after initiation of albendazole. The patient completely recovered and received albendazole treatment 3 months after surgery to maximize the chances of eradication.6