abdomen

Echinococcosis

March 3rd, 2021

Cystic echinocccosis (CE), also known as hydatid disease, is caused by infection with the larval stage of Echinococcus granulosus, a ~2-7 millimeter long tapeworm found in dogs (definitive host) and sheep, cattle, goats, and pigs (intermediate hosts).

CT scan showing hepatic hydatid cyst with dilatation of left and right intra hepatic duct.

Cyst classification:

I: simple cyst with no internal architecture

II: cyst with daughter cyst(s) and matrix

IIa: round daughter cysts at the periphery

IIb: larger, irregularly shaped daughter cysts occupying almost the entire volume of the mother cyst

IIc: oval masses with scattered calcifications and occasional daughter cysts

III: calcified cyst (dead cyst)

IV: complicated cyst

Cystic echinocccosis (CE), also known as hydatid disease, is caused by infection with the larval stage of Echinococcus granulosus, a ~2-7 millimeter long tapeworm found in dogs (definitive host) and sheep, cattle, goats, and pigs (intermediate hosts).

Cystic hydatid disease usually affects the liver (50–70%) and less frequently the lung, the spleen, the kidney, the bones, and the brain.

Liver hydatidosis can cause dissemination or anaphylaxis after a cyst ruptures into the peritoneum or biliary tract.

Infection of the cyst can facilitate the development of liver abscesses and mechanic local complications, such as mass effect on bile ducts and vessels that can induce cholestasis, portal hypertension, and Budd-Chiari syndrome.

The modern treatment of hydatid cyst of the liver varies from surgical intervention to percutaneous drainage or medical therapy.