hydatidosis due to the cestode echinococcus granulosus is a disease reported globally , but it is endemic in asia , the middle east , north africa and australia . it is especially far more frequent in mediterranean countries ( 1 , 2 ) . the adult taenia lives in the small intestine of carnivores such as dogs , foxes , and wolves as the main host . taenia eggs are excreted in the feces of these animals and either directly or by contamination of plants , fruits or vegetables , enters the gut of herbivores where the enzymes dissolve the eggs and the larvae are released ( 3 ) . the parasite again enters the main host as these contaminated animals are eaten by carnivores . man is an intermediate or accidental host of this parasite , and is infected by consuming contaminated plants or vegetables , or by contact with dogs ( 4 ) . although patients may remain asymptomatic for many years or have only mild nonspecific symptoms , they might experience life - threatening complications . but since the cyst grows very slowly the disease is diagnosed with long delays after infection . in july 2006 a 14-year - old male patient was admitted to ghaem general hospital in mashhad , iran with 3 days history of complaining acute right lower extremity pain . he lived in rural area and had no past medical or surgical history . in the first physical examination , the affected leg observed pallor , cold slightly tender , and without pulses . on further examination , his heart rate was 70 per minute with a blood pressure of 100/60 mmhg . on cardiac auscultation , a low pitched 2/6 systolic murmur was audible at left lower sternal border with no radiation and clear lung fields . femoral angiography demonstrated a filling defect in the right common , internal and external iliac arteries and complete occlusion of external iliac and common femoral arteries with a poor collateral circulation . the patient was prepared for elective explorative vascular surgery . in surgical exploration of the femoral artery was done on 18 july 2006 , by open incision showed an unusual filling defect expanding the arterial lumen . after the first surgery , the histopathologic investigation reported hydatid cysts . subsequently medication therapy with albendazol at a dose of 10 mg per kg administrated for 10 days and he also underwent further investigation . echocardiography revealed a mobile mixed mass lesion of 4.0 x 3.5 cm in dimensions with a 6 mm pedicule ( fig . 1a , 1b ) , located at the anterior free wall with bulging into the left ventricle . echocardiography revealed a mobile mixed mass lesion of 4.0  3.5 cm in dimensions with a 6 mm pedicule the patient underwent cardiac surgery on 1 august 2006 through a median sternotomy and general anesthesia . cardiopulmonary bypass using bicaval cannulae and an arterial cannula positioned in the ascending aorta . the myocardium was opened and the mass was seen in the interventricular septum and it was totally removed . postoperative gross and histopathological examination of the excised mass revealed a complicated hyda - tid cyst confirming complete excision ( fig . post - operative histopathological examination of the excised mass performing a hematoxylin eosin stain the postoperative period was uneventful . he was discharged with good condition after 7 days with prescription of a 3-month course of albendazole ( 200 mg twice daily ) . the patient was asymptomatic and the sixth month and one year post - operative echocardiography no further accumulation was found . the follow - up of the patient for 7 years by clinical and serological tests showed no evidence of recurrence . human hydatidosis is typically due to infection with the canine tapeworm e. granulosus ( 4 ) . dogs and other carnivores are the primary host and sheep the intermediate host , whereas humans are the accidental / intermediate host who do not complete the life - cycle of the parasite . humans usually become affected by the ingestion of food or milk or water contaminated by dog faeces containing the ova of the parasite ( 3 ) . when a human ingests the eggs , embryos escape from the eggs , penetrate the intestinal mucosa , and enter the portal circulation . most are filtered out by the liver or the lungs , but some escape into the general circulation to involve the brain , kidneys , bones , heart , and other tissues ( 4 ) . the diagnosis is usually made by combination of clinical findings , imaging and serological tests . also a high suspicion and history of exposure in an endemic area gives clue to the diagnosis ( 3 ) . they most commonly affect the left ventricle ( 55 - 60% ) , but also the right ventricle , left atrium ( 8% ) , pulmonary artery , pericardium ( 7 - 8% ) and the interventricular septum ( 5 - 9% ) . the clinical presentation of cardiac hydatid disease is variable and the diagnosis is difficult . since cystic mass grows slowly , it is usually asymptomatic or can produce atypical or mild symptoms depending on localization ; however , rupture of the hydatid cysts may induce embolism or life - threatening anaphylactic shock ( 5 , 7 , 8).when the interventricular septum is involved complications such as anaphylaxis and embolisation into pulmonary and systemic sites can occur ( 6 ) . surgical treatment is the only option for cardiac hydatid disease since medical therapy does not offer insurance against rupture of the cyst and its potential complications ( 3 ) . resection of an intracardiac cyst by open cardiac surgery is recommended to avoid the grave complication of rupture , which is as common as 39 % based on literature ( 2 , 3 ) . in our case the importance of our case rests in the unusual location of the hydatid cysts and also it s unusual presentation . in such cases , differential diagnosis should include cardiac tumors , thrombus , myxoma and other rare intra - cardiac tumors , such a sarcoma . recurrence has been reported in 10% of the patients undergoing hydatid cyst surgery due to spillage of protoscoleces ( 9 , 10 ) . in this case , after 7 years follow - up with clinical and serological tests showed no evidence of recurrence , confirming the successful removal of the cysts . this case emphasizes that , in endemic countries , primary cardiovascular echinococcosis should be considered in the differential diagnosis and conditions . particularly when the patient report vascular or cardiac relevant manifestations or symptoms be observed in initial physical examinations .
abstracthydatid cyst disease should be considered in differential diagnosis in many doubtful clinical situations as can present with non - specific symptoms especially in the endemic areas . cardiac involvement should be considered in patients with history of previous hydatid cyst disease .. cardiac hydatid cysts account for less than 2% of all hydatid diseases . in this report 
 we aimed to present a case of 14-year - old boy with the diagnosis of occlusion of artery of the right lower extremity . 
 surgical exploration of the femoral artery revealed multiple hydatid cysts . 
 echocardiography showed a mobile mixed mass lesion . 
 complete resection of the mass was done from interventricular septum . 
 histo - pathological examination of the removed tissue revealed a complicated hydatid cyst and complete mass excision was confirmed . in this case 
 a 7 year clinical and serological tests evaluation follow - up after surgical treatment showed no evidence of recurrence . 
 the finding of this case emphasizes that in endemic countries , primary cardiovascular echino - coccosis should be considered in differential diagnosis .