endemic areas are located in the middle east asia , south america , australia , new zealand , and alaska , where people raise sheep and cattle .
hydatid disease is a major health problem in many developing countries . because of an expanding economy
the number of foreign nationals has significantly increased in korea in recent years . in 1988 ,
the total number of legally registered foreign nationals was approximately 6,500 ; this has increased to over 1.2 million people according to 2010 estimates .
even though korea is not an endemic area for hydatid disease , the number of people from such endemic areas is increasing continuously .
humans are an intermediate host of e. granulosus through ingestion of water or vegetables contaminated by its eggs .
usually , it takes 3 - 6 years for the hydatid cyst to grow up to the size of a hen 's egg , so there is an adequate delay for clinical manifestations to appear in a new local if people relocate from an endemic area .
echinococcus , usually called the flat worm , is classified as a member of the taeniidae family .
it is approximately 5 mm long and the adult resides in the bowel lumen of the final host or lumen of the dog .
the adult worm lives in the proximal jejunum of the definitive host and attaches to the mucosa using hooklets .
its eggs are excreted in the host 's feces and when ingested by an appropriate intermediate host , such as sheep , cattle , or humans , the embryos break out from the eggs , then penetrate the intestinal mucosa and enter the systemic circulation .
once the parasitic embryo passes through the intestinal wall , it can reach the portal venous or the lymphatic system .
the liver plays an important defensive role and is the most commonly involved site ( 75% ) , subsequently there is pulmonary involvement ( 15% ) , which acts as the second site of involvement for hydatid cysts .
other systemic dissemination may occur at almost any anatomical location in the human body . however , primary renal hydatid cysts are very rare . from a 10-year case review of 144 renal hydatid cysts in tunis , one of the most affected endemic areas , patients ranged in age from 8 to 65 years , with a mean age of 35 years .
women were more affected than men ( 87 vs 57 ) because of prolonged exposure to domestic animals at home .
it is assumed that the cysts pass through the portal system into the liver and retroperitoneal lymphatics to reach the kidneys .
the most frequent clinical manifestations are abdominal pain and hydaturia as a result of rupture of the cyst into the collecting system of the patient , typically passing collapsed daughter cyst - like material in the urine .
radiologic studies are suggestive , but usually inconclusive , because the usual findings of complicated cysts in renal echinococcosis can mimic renal malignancies or a benign ureteropelvic junction obstruction . here
, we report a rare case of a renal hydatid cyst in a female patient from uzbekistan that was preoperatively misinterpreted as a renal cell carcinoma .
a 64-year - old female patient presented with complaints of a 2 month history of left flank pain .
there was no history of fever , hematuria , or pyuria . upon admission , vital signs were normal and the patient was stable .
previously , she was living in a rural area of uzbekistan and working as a housekeeper .
physical examination revealed mild costovertebral angle tenderness , but there was no palpable left flank mass .
routine hematology and biochemical tests revealed a mild leukocytosis ( 13,200 mm ) , but there was no eosinophilia ( 5% ) .
a computed tomography scan of the abdomen and pelvis demonstrated a 6.2-cm left renal cystic lesion in the upper to midpole of the kidney with soft tissue infiltration to anterior perirenal fascia .
this lesion was thought to represent a renal malignancy , leading to a decision to perform a nephrectomy .
a 7-cm supraumbilical midline incision was made for a hand port and a camera was placed through a 10-mm umbilical port .
a 10-mm working port for introduction of the operating instrument was made in the midclavicular line 4 fingers above the level of the umbilicus .
the surgical approach to the kidney was prepared , and the perinephric space was entered by incision into gerota fascia on the lateral aspect of the kidney .
the renal artery was divided into 2 branches and 1 vein and the major vessels were clamped with a hemolock . for specimen removal , a lap sac was utilized .
a drain was brought out through a separate stab incision . the kidney specimen measured 12.275.2 cm in size .
the entire mass was a large unilocular cyst with multiple smaller associated cysts without any grossly apparent renal parenchyma ( fig .
the outermost pericystic layer was composed of fibro - collagenous tissue along with an eosinophilic infiltrate and the innermost germinal layer was apparently comprised of degenerated brood capsules ( fig .
3 ) . at 400 magnification , multiple protoscolex - like structures were found inside of the cyst ( fig .
preoperative diagnosis of hydatid cysts could result from various investigations , including intravenous pyelography ( ivp ) , ultrasonography , and serology tests .
computerized scans are indicated when a clarification of the differential diagnosis of solid tumors is required .
usually , renal hydatid cysts present as a single large cyst with smaller daughter cysts of varying sizes . in our case ,
ultrasonography and ct scan showed a typical daughter cyst within the 6 cm sized mother cyst .
however , the sensitivity of serological tests is influenced by the site and maturation of the hydatid cysts .
hydatid cysts in human lungs , spleen , or kidney tend to be associated with lower serum antibody levels .
eosinophilia is reported in 25 - 50% of hydatid disease cases and may occur in other parasitic diseases .
renal sparing or total nephrectomy is available irrespective of the surgical method , so laparoscopic removals of renal hydatid cysts have been reported .
if preoperative diagnosis of a hydatid cyst is made , the area around the cyst can be carefully isolated by gauze packs and initial cyst aspiration and replacement of the cystic liquid with scolicide can be performed .
a second technique , the so called partial cysto - pericystectomy is also an available option : the cyst , including the hydatid membrane and the daughter cysts , are opened and removal of the laminated membrane with scolicide - soaked swabs is performed .
the margin of the remnant pericyst tissue is then sutured by running absorbable sutures . as a general rule , nephrectomy must be reserved for a non - functioning kidney as a renal hydatid cyst is a benign infection .
so , in localized cases , focal or partial resection would be better option if a preoperative diagnosis is possible . in cases of a suspected renal mass , complete removal of a definite lesion is the first priority in non - endemic areas , such as korea .
even though the patient was from uzbekistan , we did not consider a hydatid cyst as a diagnostic option . in a tunisian study of 175 renal masses ,
hydatid cysts were found in 32% of cases , malignant tumors in 36.5% , simple cysts in 27% , and benign tumors in 4.5% . if the possibility of a hydatid cyst were considered in the present case , a different approach could have been considered .
hydatid cysts at unusual sites , such as the kidney , especially in non - endemic areas , can lead to difficulties in the diagnosis and management of this unfamiliar parasite , possibly leading to complications , such as an acute surgical emergency or a chronic illness leading to morbidity .
although hydatid cysts of the kidney are relatively rare , this disease must be considered in people with renal cystic masses from endemic countries .
a multimodality approach , which includes clinical history , hematology , serology , ultrasonography , ivp , or ct , with histo - pathological confirmation is required for optimal management .
the diagnosis of a renal hydatid cyst is based primarily on imaging findings . in korea , it is uneasy to differentiate a renal hydatid cyst from other renal diseases , because a hydatid cyst is not a familiar disease to korean clinicians . actually , there was 1 renal hydatid cyst case reported in korea . in this case ,
ct scan shows the simple cyst lesion with a daughter cyst and slight enhancement of the cystic wall .
korea is becoming more multi - ethnic because of various economic and socio - political factors .
a total of 33 echinococcosis cases have been reported in the literature based on the diagnosis of the parasite ; these patients included 25 koreans , 7 uzbeks , and 1 mongolian .
with the exclusion of 2 korean patients in whom the origin of infection is unclear , the remaining 31 patients are considered as imported echinococcosis .
furthermore , more koreans travel or work abroad , and imported cases are increasing steadily . finally , for an enlarged kidney with a renal mass , especially in someone from an endemic area , hydatid cyst should be included in the differential diagnosis , even though korea is not an endemic area .
 primary renal echinococcosis , a rare disease involving the kidney , accounts for 2 - 3% of human echinococcosis . 
 a 64-year - old female patient from uzbekistan presented with complaints of left flank pain . 
 a ct scan revealed a cystic mass in the upper to midpole of the left kidney . 
 we regarded this lesion as a renal malignancy and hand - assisted laparoscopic radical nephrectomy was performed to remove the renal mass . 
 the mass consisted of a large unilocular cyst and multiple smaller cysts without any grossly visible renal tissue . 
 the final pathologic diagnosis was a renal hydatid cyst . 
 for patients from endemic areas , hydatid cyst should be included in the differential diagnosis . here , 
 we present a case of renal hydatid cyst in a female patient who relocated from uzbekistan to korea . 
INTRODUCTION
CASE RECORD
DISCUSSION