HYDATID CYST HYDATID CYST DISEASEDISEASE

1 Echinococcus granulosus1 Echinococcus granulosus cystic echinococcosiscystic echinococcosis

2 2 Echinococcus multilocularisEchinococcus multilocularis alveolar echinococcosisalveolar echinococcosis

Echinococcus granulosus

Layers of hydatid cystLayers of hydatid cyst

• Pericyst or adventitia Pericyst or adventitia

• The endocyst or laminated layer The endocyst or laminated layer

• Germinal layer Germinal layer The germinal layer produces clear fluid which The germinal layer produces clear fluid which

attains a pressure of up to 300 mm of water, attains a pressure of up to 300 mm of water, keeping the endocyst in intimate contact keeping the endocyst in intimate contact with the pericyst. The endocyst receives its with the pericyst. The endocyst receives its sustenance from the pericyst. sustenance from the pericyst.

Cyst layers and contents

• The growth rate of cysts is highly The growth rate of cysts is highly variable and may depend on strain variable and may depend on strain differences and cyst location. differences and cyst location. Estimates of the average increase Estimates of the average increase of cyst diameter vary of cyst diameter vary (approximately 1.5-2 cm/year). (approximately 1.5-2 cm/year).

Clinical presentationClinical presentation : : The clinical features of CE are highly variable. The The clinical features of CE are highly variable. The

spectrum of symptoms depends on the following: spectrum of symptoms depends on the following: • Involved organs Involved organs • Size of cysts and their sites within the affected organ or Size of cysts and their sites within the affected organ or

organs organs • Interaction between the expanding cysts and adjacent Interaction between the expanding cysts and adjacent

organ structures, particularly bile ducts and the organ structures, particularly bile ducts and the vascular system of the liver vascular system of the liver

• Complications caused by rupture of cysts Complications caused by rupture of cysts • Bacterial infection of cysts and spread of protoscolices Bacterial infection of cysts and spread of protoscolices

and larval material into bile ducts or blood vessels and larval material into bile ducts or blood vessels • Immunologic reactions such as asthma, anaphylaxis, or Immunologic reactions such as asthma, anaphylaxis, or

membranous nephropathy secondary to release of membranous nephropathy secondary to release of antigenic materialantigenic material

Lab Studies:

• Generally, routine laboratory tests do not Generally, routine laboratory tests do not show specific results.show specific results.

In patients with rupture of the cyst in the In patients with rupture of the cyst in the biliary tree, marked and transient biliary tree, marked and transient elevation of cholestatic enzyme levels elevation of cholestatic enzyme levels occurs, often in association with occurs, often in association with hyperamylasemia and eosinophilia (as hyperamylasemia and eosinophilia (as many as 60%).many as 60%).

• Casoni or intradermal test Casoni or intradermal test o Indirect hemagglutination test and Indirect hemagglutination test and

enzyme-linked immunosorbent assay enzyme-linked immunosorbent assay are the most widely used methods for are the most widely used methods for detection of anti-Echinococcus detection of anti-Echinococcus antibodies (immunoglobulin G antibodies (immunoglobulin G [IgG]).These tests give false positive [IgG]).These tests give false positive results in cases of schistosomiasis and results in cases of schistosomiasis and nematode infestations that is why they nematode infestations that is why they are not specific for diagnosing are not specific for diagnosing hydatidosis.hydatidosis.

• Immunoelectrophoresis : depends on Immunoelectrophoresis : depends on the formation of specific arc of the formation of specific arc of precipitation ( called arc 5 ) which is precipitation ( called arc 5 ) which is highly specific and can be used to highly specific and can be used to exclude cross-reactions caused by exclude cross-reactions caused by noncestode parasites noncestode parasites

Imaging Studies: Imaging Studies:

• Plain radiographyPlain radiography

• Ultrasound examinationUltrasound examination

• CT scaningCT scaning

• MRIMRI

Treatment :Treatment :• A- Medical: A- Medical:

• Two benzimidazolic drugs, mebendazole and Two benzimidazolic drugs, mebendazole and albendazole, are well tolerated but show albendazole, are well tolerated but show different efficacy.different efficacy.

Praziquantel : it belongs to isoquinoline group Praziquantel : it belongs to isoquinoline group and has been widely used in schistosomiasis and and has been widely used in schistosomiasis and it has been shown to be a most active and rapid it has been shown to be a most active and rapid scolicidal agent but it has poor effect on germinal scolicidal agent but it has poor effect on germinal layer so it is of choice for prophylaxis in pre and layer so it is of choice for prophylaxis in pre and post operative period in order to prevent post operative period in order to prevent secondary implantation of spilled protoscoleces . secondary implantation of spilled protoscoleces .

B- Surgical: B- Surgical:

Surgery was the only treatment available Surgery was the only treatment available before the introduction of anthelmintic before the introduction of anthelmintic drugs. It is considered the first choice of drugs. It is considered the first choice of treatment for echinococcosis but is treatment for echinococcosis but is associated with considerable morbidity, and associated with considerable morbidity, and recurrence rates (2-25%). recurrence rates (2-25%).

Minimally invasive treatment Minimally invasive treatment

• PAIRPAIR