most frequently caused echinococcosis is by e. granulosus commonly seen in the mediterranean region , africa , south america , middle east , australasia , and new zealand . alveolar echinococcosis caused by e. multilocularis is less prevalent and has been reported only from iran , turkey , iraq , and tunisia . the reported annual morbidity from the disease in humans is 1.04 - 2.4 per 1,000,000 although the actual rates are thought to be more than twice because of underreporting . the unilocular cystic form caused by e. granulosus is far more common than the rare multilocular alveolar form caused by e. multilocularis . diagnostic modalities include clinical , radiological , and serological examinations , done before the surgical treatment . the aim of the present study was to gain an insight into the diverse clinicopathological spectrum of pulmonary hydatidosis . a total of eight cases with lung involvement by hydatid disease over a period of ten years ( 2003 - 2012 ) were included in the study . the demographic data including the clinical features , radiological findings , and other organ involvement were compiled from the records . the clinical features like history of cough , dyspnea , expectoration , fever , or anaphylaxis were searched for in the medical records . detailed radiological findings like solitary or multiple cysts , simple or complicated cysts , unilateral or bilateral lung involvement , and involvement of other organs like liver and spleen were recorded . the specimens received had been earlier fixed in buffered formalin and processed for paraffin sections . the slides were retrieved from the archives and the routine hematoxylin and eosin stained sections were studied . the parasite morphology , the ectocyst , endocyst along with brood capsules , and pericyst were studied . the treatment rendered , whether medical or surgical , was also noted from the available records . during the study period a total of eight cases were diagnosed as pulmonary hydatid disease . there were five males and three females . six patients had solitary cysts involving the lung while bilateral lung involvement was seen in two cases . hooklets were observed in six cases while a scolex was seen in a single case [ figure 2 ] . the pericyst composed of inflammatory granulation tissue with prominence of eosinophils was seen in four cases . gross photograph showing multiple fluid - filled cysts of variable sizes and a laminated whitish membranous layer clinical and radiological features in pulmonary hydatidosis photomicrograph showing scolices with the presence of scimitar - shaped hooklets ( h and e , 600 ) . most of the cysts are acquired in childhood and are asymptomatic for years before being diagnosed radiologically on x - ray chest , incidentally most often . hydatid cysts in the lungs are multiple in 30% of cases with bilaterality seen in 20% and the preferential location being the lower lobes in 60% of the cases . bilateral lung involvement was seen in two cases and cysts were multiple in a single case in our study . sudden coughing attacks , hemoptysis , and chest pain are the most common clinical symptoms . fever and cough were the most common symptoms in our study . in the event of a cyst rupture cyst fluid , membranes , and scolices following cyst rupture allergic reactions may develop ; however , fatal anaphylaxis is uncommon . in our study the diagnosis of pulmonary hydatid disease rests on clinical , radiological , and serological examinations . air - fluid levels , water - lily sign , meniscus sign , and a cavity may be seen in complicated cysts . the complicated cysts can be accurately localized on computed tomography ( ct ) , which facilitates the surgical management . apart from the conventional appearances of hydatid cysts on ct scanning of the lung , some unusual ct features of pulmonary hydatidosis include a crescent - like rim of air at the lower end of the cyst ; inverse crescent sign and a bleb of air dissecting into the cyst wall resembling the shape of a ring ; signet ring sign . moreover , high ct density indicating fibrosis or infection of the cyst and/or thick wall should not negate a diagnosis of hydatid disease . bronchoscopy may allow a definitive diagnosis of pulmonary hydatid disease in patients with atypical clinical and radiological features . lungs , liver , and spleen are the frequent ones while the heart , pericardium , orbit , gastric wall , mediastinum , subcutaneous space , muscle , and adrenal gland are relatively infrequent . accompanying hepatic and/or splenic cysts are well seen on ultrasonography ( usg ) . the hepatic cysts in pulmonary hydatidosis may be seen in 6 - 34.8% of patients . three patients had associated hepatic cysts and two had splenic cysts along with pulmonary cysts in our study . percutaneous aspiration can help in reaching a confirmatory diagnosis by demonstrating scolices , hooklets , or membranes . however , the possibility of cyst rupture with dissemination of contents and anaphylaxis hinders the procedure for routine diagnostic use . the histopathological findings described include the three layers : ( i ) the outermost pericyst , composed of dense fibrocollagenous tissue with inflammatory cells ; ( ii ) the laminated acellular eosinophilic ectocyst ; and ( iii ) the inner germinal layer or the endocyst from which the brood capsules containing scolices and hooklets develop . we observed the ectocyst in all the eight cases , endocyst with brood capsules in five cases , and pericyst in four cases . the cysts of e. multilocularis differ from those of e. granulosus and consist of a spongy pale tissue containing multiple scattered cysts which are lined by a laminated membrane which can be seen microscopically . surgical intervention should consist of closing all bronchial openings after the membrane of the cyst has been removed . there is an increased possibility of rupture during the separation of the pericyst from the laminated membrane during the enucleation procedure especially in larger cysts . pericystotomy procedure may not be advocated as it prolongs the surgery time and is associated with an increased risk of hemorrhage . surgical lobectomy , done in four cases in the current study is the procedure of choice in large cysts which involve more than half of the lobe , cysts with severe suppuration not responsive to other treatments , multiple cysts and in cases with bronchiectasis , pulmonary fibrosis or severe hemorrhage subsequent to pulmonary hydatidosis . medical therapy with benzimidazoles ( mebendazole and albendazole ) with or without praziquantel is indicated in disseminated disease , including secondary lung or pleural hydatidosis , high - risk patients for surgery , spillage during surgery , and small pulmonary hydatid cysts . however , there is no consensus regarding the choice of surgical procedure but lung preserving surgery is preferred . patients with a pleural lesion must be followed up on a regular basis for any signs of recurrence . recurrence reported is between 0 and 1.45% of the patients who are on a regular long - term follow - up . anaphylaxis , although rarely seen , may be a disastrous event . high index of clinical suspicion and mass awareness for interruption of transmission of parasite can lead to proper treatment and possible eradication .
background : hydatid disease is caused by the larval stage of echinococcus . 
 liver is the most commonly involved organ followed by the lungs . 
 pulmonary hydatidosis can be primary or secondary . 
 the disease may be asymptomatic for several years . 
 cause of concern is the fatal anaphylaxis , which may be life threatening.materials and methods : the present retrospective study is over a period of ten years ( 2003 - 2012 ) . the demographic data including the clinical features , radiological findings , other organ involvement , surgical and medical management done and histopathological findings were compiled from the records.results:during the study period a total of eight cases , five male and three female , with age ranging from eight to 43 years were diagnosed as pulmonary hydatid disease . five patients had presented with complicated cysts . 
 six patients had solitary cysts involving the lung while bilateral lung involvement was seen in two cases . 
 one patient had multiple pulmonary cysts . 
 three patients had associated cysts in liver and two in spleen . 
 surgical lobectomy was done in four cases . 
 histopathology showed acellular laminated ectocysts in all the cases , whereas endocyst with brood capsules was seen in five cases.conclusions:pulmonary hydatidosis is not uncommon . 
 anaphylaxis , although rarely seen , may be a disastrous event . 
 high index of clinical suspicion and mass awareness for interruption of transmission of parasite can lead to proper treatment and possible eradication .