Parasites, Infection, Cysts, Education, Diagnostic procedure, Ultrasound, MR, CT, Liver, Abdomen
A. Martin1, D. Petruneac2; 1Targu-Mures/RO, 2Targu Mures, Mures/RO
Hydatid disease ( HD) is a zoonotic infection with endemic world-wide distribution,
is due to the larval stage of the tapeworm Echinococcus.( fig.1)
Humans may become intermediate hosts through contact with a definitive host (usually a domesticated dog) or ingestion of contaminated water or vegetables.
The parasite passes through the intestinal wall to reach the portal venous system or lymphatic system,
the liver acts as the first line of defense and is therefore the most frequently involved organ.
hydatid disease involves the liver in approximately 75% of cases,
the lung in 15%,
and other anatomic locations in 10%. Once in the human liver,
depending on host tissue resistance cysts grow up to 1 cm during the first 6 months.
There are many potential local complications (eg,
transdiaphragmatic thoracic involvement,
perforation into hollow viscera,
portal vein involvement,
abdominal wall invasion).
Secondary involvement due to hematogenous dissemination may be seen in almost any anatomic location
The hydatid cyst has three layers: the outer pericyst,
the middle laminated membrane,
the inner germinal layer (the middle laminated membrane and the germinal layer form the true wall cyst referred to as the endocyst),
daughter vesicles and cyst fluid.