hydatid 
 disease is a parasitic infection caused by echinococcus , which is endemic in 
 farming areas . it primarily involves the liver and presents as the gastrointestinal 
 manifestations such as abdominal pain , hepatomegaly , anorexia , vomiting , and 
 jaundice . the primary involvement of the pelvic cavity is a very rare entity and 
 patients usually present with pressure symptoms affecting the adjacent organs [ 15 ] . herein , we report this interesting case that presented differently and also 
 discuss the significance of the awareness of physicians about this rare but 
 well - documented disease . a 34-year - old woman was admitted to our 
 center with complaints of lower abdominal pain , anorexia , constipation , and 
 significant weight loss ( more than 10 kg during 4 months ) . as the patient had severe 
 constipation and other gastrointestinal symptoms , colonoscopy had been carried 
 out in another center with normal findings . 
 on pelvic examination a nontender , uniformly cystic 
 mass approximately 28-week size was palpated . laboratory investigations including blood sugar , blood urea nitrogen , 
 creatinine , liver enzymes , and urinalysis were normal and stool occult blood 
 was negative . complete blood count was normal 
 except mild anemia ( hb : 7 gr / dl ) . on transabdominal 
 ultrasound , multiple anechoic masses were demonstrated in the pelvic and 
 uterine cavities . for further delineation of the cystic masses and disease 
 extension in the pelvic cavity , computed tomography ( ct ) scan was performed , that 
 revealing multiple cystic space - occupying lesions in the pelvic cavity , 
 involving the uterus , broad ligament , and adnexa ( figure 1 ) . the patient 
 underwent an exploratory laparotomy under general anesthesia for further 
 diagnosis of the cystic mass , and ruling out of the genitourinary malignancy . preoperative laboratory evaluation including hiv antibody , 
 vdrl test , hbs antigen , and hcv antibody assay were normal . additionally , whole 
 body bone scan , chest and abdominal ct scan were also performed that revealed 
 unremarkable results . on the 10th day of her admission after obtaining the 
 informed consent , numerous ovarian and paraovarian cystic masses densely adhered to the uterus , 
 to the pelvic side wall , and to the fallopian tubes were demonstrated . one of 
 the cysts was removed completely and sent to the laboratory and this surgical 
 specimen was diagnosed as the hydatid cyst . due to extensive involvement of the 
 uterus , adnexa , and broad ligament , complete removal of the cysts and preservation 
 of the all reproductive organs was impossible ; furthermore complete removal of 
 the cysts due to the high risk of rupture could be life threatening , so after 
 obtaining the signed consent we decided to perform removal of the cysts of the 
 right adnexa and uterus with preservation of them and left side salpingoophorectomy . microscopic 
 examination disclosed the scolices of echinococcus granulosis with 
 adjacent laminated membrane and confirmed the diagnosis ( figure 2 ) . albendazole 
 ( 800 mg per day ) as adjuvant therapy was administered for 4 months 
 postoperatively . blood count and liver transaminases were checked during the 
 course of therapy which showed normal results . at 6-month follow - up the patient 
 was doing well with no detectable abnormality on follow - up ultrasound . hydatid disease is a parasitic disease 
 caused by the larval stage of the tapeworm echinococcus granulosus . while 
 liver and lung are the most commonly affected areas in adults , hydatid 
 cysts may develop in almost any part of body [ 1 , 2 , 4 ] . primary hydatidosis of 
 the pelvic cavity is very rare but well documented in endemic areas such as the 
 mediterranean countries , south america , the middle east , and australia 
  [ 1 , 3 ] . our patient is 
 the first reported case of primary hydatidosis of the pelvic cavity from iran 
  and underlines the difficulties in the diagnosis of cases with striking 
 resemblance to malignant disease of the reproductive tract . to our knowledge , 
 the primary involvement of the pelvic cavity usually presents with pressure 
 symptoms affecting the adjacent organs   and this manifestation has been 
 reported exceedingly rare in the english literature so far . diagnosis of 
 the hydatid cyst is mainly on the basis of serologic tests and/or ultrasonography 
 and ct scan . previous history of hydatid cysts or exposure to dog and farm 
 animals should raise the suspicion of this diagnosis . following 
 the surgical diagnosis in our patient , we 
 inquired about such a history in our patient but revealed no identifiable 
 exposure . specific serological methods using specific antigens , 
 especially native agb , have been recommended for proper diagnosis because the serological 
 tests using crude antigens are sensitive , but their specificity is not 
 satisfactory . in one study , the enzyme - linked immunosorbent assay ( elisa ) 
 system is much more specific in detecting antihydatid cyst antibody than countercurrent 
 immunoelectrophresis ( cciep ) , while cciep is more sensitive in detecting 
 antihydatid cyst antibody . interestingly , 
 we carried out the cciep assay immediately 
 after the confirmatory result of the pathology that was positive for hydatid 
 cyst therefore serologic tests in the patients with suspicious diagnosis may 
 render the diagnosis of the hydatid cyst . ultrasound is an important 
 imaging modality for hydatid disease and may clearly demonstrate the floating 
 membranes , and daughter cysts characteristically seen in purely cystic lesions . the ultrasonographic findings range from purely cystic lesions to a completely 
 solid appearance . in another study , cciep could detect only 62.0% of 
 cases , whereas the pathology and ultrasound results were positive for 96.3% of 
 cases . this study emphasized the usefulness of ultrasound and suggested that cciep 
 may be useful for diagnosing cystic echinococcus only in doubtful cases 
 . ct and magnetic resonance 
 imaging ( mri ) play a key role in recognizing the complications such as rupture 
 and infection of cysts associated with hydatid disease . we believe that ct scan  because of its 
 capability for better evaluation of the cystic masses , and better demonstration 
 of their extension in the pelvic cavity as well as excellent depiction of the 
 visceral organs involvement  is superior to 
 the ultrasonographic examination . the scan in suspected hydatid disease should 
 include the whole abdomen from liver to pelvis and a chest radiograph should 
 also be obtained . skin tests , complement 
 fixation , blood eosinophil count , and indirect hemagglutination tests can also 
 be used for diagnostic purpose however their tendency toward the false - positve 
 results limits their validity . the gold standard test for diagnosis of 
 hydatidosis is microscopic examination that shows the laminated membrane and scolices 
 [ 14 , 69 ] . complete removal of the 
 parasitic cysts and fluid is the major advantage of the surgery . single cysts 
 are easy to excise but due to the risk of adhesions , excision of the multiple 
 cysts may be difficult and even impossible [ 16 ] . we agree with this comment which 
 emphasizes that in the younger women , even in those with multiple cysts , every 
 effort should be made to preserve reproductive organs . as previously stated 
 in this case , extensive involvement and hard adhesion of the adnexa to the 
 adjacent cysts of the broad ligaments forced us to perform left - sided salpingoophorectomy . another important problem is dealing with intraoperative spillage of the cyst 
 contents that contain protoscolices and can disseminate in tissue and grow new 
 cysts . furthermore , acute anaphylactic reaction may ensue secondary to the 
 spilled cyst fluid therefore spillage should be avoided by all means [ 2 , 48 ] . the treatment of the recurrence and complications is very difficult and definition 
 of the best option needs multidisciplinary approach therefore medical therapy 
 should be applied postoperatively in the patients with multiple cysts and 
 multiple initial locations . the clinical manifestation of our case such as 
 severe weight loss , as well as the large multicystic mass of the pelvic cavity 
 erroneously 
 points us to the diagnosis of the ovarian malignancies . the current case 
 underlines the possibility of the striking resemblance between the clinical and 
 radiological manifestation of the hydatid cyst and malignant disease of the 
 reproductive organs which may make the correct preoperative diagnosis very 
 difficult . the tumor markers were not checked in our case however lack of the other evidences of the metastasis to the visceral 
 organs in the chest and abdominal ct scan and normal result of the bone scan 
 was the useful guidelines against the diagnosis of the ovarian malignancy . although normal results of the tumor markers such as cea and ca-125 may be 
 found in the patients with genitourinary malignancies especially ovarian 
 cancer , we note that these markers should be 
 evaluated in the patients with the suspicious diagnosis of the genitourinary 
 malignancies . in conclusion , primary hydatidosis of the pelvic cavity should 
 always be considered in the differential diagnosis of any tumor - like growing 
 mass even in the absence of accompanying involvement of liver or other visceral 
 organs . we believe that in the cases like our patient , the most important 
 factor in diagnosis of hydatid disease of the pelvic cavity is the high index 
 of suspicion about its possibility which can provide the accurate diagnosis and 
 prevent the erroneous treatment . the 
 other important consideration is the 
 accidental rupture of hydatid cyst during surgery which may be life threatening , 
 therefore preoperative diagnosis of this 
 rare lesion is very important . the patient 's history as well as the 
 serologic tests may yield important clues about the diagnosis , furthermore the 
 radiologist 's familiarity with the imaging findings of the disease is very important 
 for earlier diagnosis and an appropriate treatment .
we report and discuss a case of primary hydatidosis of the pelvic cavity in a woman who presented with severe weight loss and abdominal pain . 
 this unusual presentation was initially considered as a tumor process until surgical exploration and microscopic studies confirmed the diagnosis . 
 the gynecologists should be aware of possibility of primary hydatid cyst of the pelvic cavity and should be considered in the differential diagnosis of cystic pelvic masses , especially in areas where the disease is endemic .