History

The patient was 20 years old and presented with pain in the left hypochondrium. Clinical examination showed mild splenomegaly with no other associated signs. Abdominal ultrasound confirmed the diagnosis of splenic hydatid cyst (Figure 1A) and a complementary abdominal CT scan was requested (Figure 1B).

Diagnosis: Splenic hydatid cyst.

Commentary

The hydatid cyst of the liver is a parasitic disease due to the development of echinococcus granulosus in the body. The hepatic localization is the first localization by order of frequency followed by the pulmonary localization, splenic then the other localizations has to know (cerebral, retroperitoneal, renal, osseous and musculoskeletal) [1]. The notion of contact with dogs and breeding areas is found in half of the cases [2].

The cyst is the basic lesion of echinococcosis and is composed of three elements:
- Pericyst: Composed of inflammatory tissue of the host of origin (host organ).
- Exocyst
- Endocyst: or the proligeral membrane.

The hydatid cyst can take on several aspects in its native state, in case of partial or complete rupture which are typical and pathognomonic as the case of the "snake sign" which corresponds to a rupture of the endocyst within the hydatid cyst thus giving a detachment of the membrane with, on ultrasound imaging as well as on CT scan, the serpiginous aspect of the proligeral membrane within the hydatid cyst which remains with a liquid content without a hydro-aeric level contrary to the "nenuphar" aspect when the membrane floats within a hydro-aeric level.

Keywords: Cyst; Echinococcus granulosus; Spleen; Snake sign