--- license: apache-2.0 language: - en pipeline_tag: summarization widget: - text: "duplications of the alimentary tract are well - known but rare congenital malformations that can occur anywhere in the gastrointestinal ( gi ) tract from the tongue to the anus . while midgut duplications are the most common , foregut duplications such as oesophagus , stomach , and parts 1 and 2 of the duodenum account for approximately one - third of cases . they are most commonly seen either in the thorax or abdomen or in both as congenital thoracoabdominal duplications . cystic oesophageal duplication ( ced ) , the most common presentation , is often found in the lower third part ( 60 - 95% ) and on the right side [ 2 , 3 ] . hydatid cyst ( hc ) is still an important health problem throughout the world , particularly in latin america , africa , and mediterranean areas . turkey , located in the mediterranean area , shares this problem , with an estimated incidence of 20/100 000 . most commonly reported effected organ is liver , but in children the lungs are the second most frequent site of involvement [ 4 , 5 ] . in both ced and hc , the presentation depends on the site and the size of the cyst . hydatid cysts are far more common than other cystic intrathoracic lesions , especially in endemic areas , so it is a challenge to differentiate ced from hc in these countries . here , we present a 7-year - old girl with intrathoracic cystic mass lesion , who had been treated for hydatid cyst for 9 months , but who turned out to have oesophageal cystic duplication . a 7-year - old girl was referred to our clinic with coincidentally established cystic intrathoracic lesion during the investigation of aetiology of anaemia . the child was first admitted with loss of vision in another hospital ten months previously . the patient 's complaints had been attributed to pseudotumour cerebri due to severe iron deficiency anaemia ( haemoglobin : 3 g / dl ) . chest radiography and computed tomography ( ct ) images resulted in a diagnosis of cystic intrathoracic lesion ( fig . the cystic mass was accepted as a type 1 hydatid cyst according to world health organization ( who ) classification . after 9 months of medication , no regression was detected in ct images , so the patient was referred to our department . an ondirect haemagglutination test result was again negative . during surgery , after left thoracotomy incision , a semi - mobile cystic lesion , which was almost seven centimetres in diameter , with smooth contour , was found above the diaphragm , below the lung , outside the pleura ( fig . the entire fluid in the cyst was aspirated ; it was brown and bloody ( fig . 2 ) . the diagnosis of cystic oesophageal duplication was considered , and so an attachment point was searched for . it was below the hiatus , on the lower third left side of the oesophagus , and it also was excised completely through the hiatus . pathologic analysis of the specimen showed oesophageal mucosa with an underlying proper smooth muscle layer." example_title: Summarization Example 1 ---