copper plays a role as a cofactor for various enzymes in the human body , and is indispensable for myeloid and neurological structure and function . copper deficiency leads to functional disorders of hematopoiesis such as anemia and neutropenia , as well as neurological disorders such as myelopathy . copper is absorbed mainly from the duodenum and proximal jejunum , and partly from the stomach . some recent reports have noted that patients on enteral nutrition through a jejunostomy in long - term - care hospitals sometimes experience copper deficiency . however , it is extremely rare to find patients with copper deficiency several months postoperatively , regardless of enteral nutrition through the jejunostomy . we report herein the case of a patient who experienced copper - deficiency anemia after esophagectomy and subsequent enteral nutrition through the jejunostomy . a 73-year - old man with a chief complaint of dysphagia was diagnosed with thoracic esophageal cancer at a local hospital . he had no medical history of copper metabolic disorders such as menkes disease or occipital horn syndrome , and family history was not contributory . he had been smoking 20 cigarettes a day for 30 years and drinking 200  ml of red wine a day for 50 years . preoperative diagnosis was ct1bn0m0 cstage ia ( uicc tnm classification , 7th edition ) , and the patient underwent esophagectomy with two - field lymphadenectomy followed by reconstruction with a gastric tube via retrosternal route and jejunostomy . the jejunostomy tube ( 9 fr ) was inserted through the antrum of gastric tube , and the end of it was located at the ligament of treitz through pylorus . operation time was 9  h 52  min , and blood loss was 2420  ml , which was highly invasive to him . it was fixed through emergent reoperation on the same day , but the patient developed subsequent severe pulmonary failure and required long - term artificial ventilatory support . oral intake was impossible due to his deteriorated deglutition ability ; therefore , nutritional management started from postoperative day 3 as enteral nutrition with a small amount of standard nutrient solution through the jejunostomy . his general condition improved , and thus the amount of nutrient solution was gradually increased to 1210  kcal of energy and 1.6  mg of copper by 1 month postoperatively . by 3 months postoperatively , inflammatory response had completely disappeared , and no signs of bleeding or deficiency of serum iron , ferritin , folic acid or vitamin 12 were noted . however , the patient was suffering continuous anemia , and required intermittent transfusions ( fig . serum levels of copper and ceruloplasmin were 7  g / dl ( normal range , 68128  g / dl ) and 8  mg / dl ( normal range , 2137  mg / dl ) , respectively . it was considered that copper deficiency was attributable to problems with the nutrition pathway , leading to copper malabsorption despite the seemingly ample copper administration . ten grams of commercially available cocoa powder ( 0.4  mg of copper ) was mixed with 100  ml of warm water , and then administered through the jejunostomy once daily in the morning ( fig . no side effects arose from cocoa supplementation , and the 9-fr nutritional tube did not become clogged by the cocoa / water mixture . serum levels of copper and hemoglobin gradually increased , reaching 76  g / dl and 9.8  g / dl , respectively , by 61 days after starting cocoa supplementation . during the supplementation period , as copper levels increased , zinc levels decreased ; however , none of the symptoms were attributable to zinc deficiency ( fig . 3 ) . since anemia was alleviated and the general condition of the patient improved , he was referred to another hospital to continue long - term rehabilitation . copper - deficiency anemia has already been reported to occur in patients receiving enteral nutrition in long - term care hospitals . however , to the best of our knowledge , this represents the first case to be reported of copper deficiency after esophagectomy despite administration of standard enteral nutrition through the jejunostomy for several months . the standard nutrient solution has been noted to lack the requisite amount of copper , so most of the formulae for current nutrient solutions have been improved to meet this requirements . the recommended daily allowance of copper by the us national academy of sciences is 900  g per day for adult men and women . japanese government recommends a dietary allowance of 700  g per day in woman and 800  g per day in men aged 18 years old and older . the patient in the present case suffered from copper deficiency despite administration of copper at 1.6  mg / day . the main reason for copper deficiency in the present case was the nutritional pathway through the jejunostomy . since nutrition bypassed the duodenum , which is the main site of copper absorption , copper deficiency must have occurred regardless of the seemingly ample administration . reported that the mean serum copper level in patients with enteral nutrition through the jejunostomy declined from 93.6  g / dl to 43.9  g / dl in 6 months . theoretically , copper deficiency can occur after other types of surgeries such as gastrectomy with roux - en - y reconstruction and pancreaticoduodenectomy because food does not pass through the duodenum in those cases . however , to the best of our knowledge , no such cases have been reported . copper deficiency in those cases may not have been fully investigated , so this issue remains to be assessed in the future . this source was selected based on the ease of obtainment and administration compared with other copper - rich foods such as crustaceans , organ meats , and beans . if this method had not worked well , we would have considered the following three methods : ( 1 ) increasing the level of copper supplementation up to 40  g / day , as described by tokuda et al . ; ( 2 ) extracting the jejunostomy tube slightly so that the end of the tube could be placed in the stomach ; or ( 3 ) intravenous administration of copper . no symptoms of zinc deficiency were encountered in this patient ; however , we recognized that monitoring of serum zinc levels is necessary when copper supplementation is performed . some reports have described advantages of postoperative enteral nutrition after major surgical operations such as esophagectomy and pancreaticoduodenectomy , and the nutritional pathway in those cases typically involves jejunostomy . the present experience highlighted the possibility of copper deficiency , even if a seemingly ample amount of copper is being administered to the patient , when enteral nutrition through the jejunostomy is continuously performed for several months postoperatively . when treating such cases , regular monitoring of serum copper levels is warranted , and copper deficiency should be considered among the differential diagnoses for anemia of unknown origin . it is extremely rare to find copper - deficiency anemia several months after esophagectomy followed by enteral nutrition through the jejunostomy . however , if anemia of unknown origin occurs in such patients , copper - deficiency anemia must be considered among the differential diagnoses . authors masatoshi nakagawa , kagami nagai , isao minami , mai wakabayashi , junko torigoe and tatsuyuki kawano have no conflict of interest or financial ties to disclose . written informed consent was obtained from the patient for publication of this case report and any accompanying images . a copy of the written consent is available for review by the editor - in - chief of this journal . isao minami , mai wakabayashi and junko torigoe involved in data collection.key learning pointsit is very rare to find patients with copper - deficiency anemia regardless of postoperative enteral nutrition . however , when enteral nutrition is given through jejunostomy , it can occur because nutrition bypass duodenum and proximal jejunum which are the main parts for copper absorption.copper-deficiency anemia is very rare after surgery . however , if patients suffer anemia of unknown origin after surgery , we should consider copper - deficiency anemia as one of differential diagnoses . it is very rare to find patients with copper - deficiency anemia regardless of postoperative enteral nutrition . however , when enteral nutrition is given through jejunostomy , it can occur because nutrition bypass duodenum and proximal jejunum which are the main parts for copper absorption.copper-deficiency anemia is very rare after surgery . however , if patients suffer anemia of unknown origin after surgery , we should consider copper - deficiency anemia as one of differential diagnoses . it is very rare to find patients with copper - deficiency anemia regardless of postoperative enteral nutrition . however , when enteral nutrition is given through jejunostomy , it can occur because nutrition bypass duodenum and proximal jejunum which are the main parts for copper absorption . however , if patients suffer anemia of unknown origin after surgery , we should consider copper - deficiency anemia as one of differential diagnoses .
introductioncopper deficiency leads to functional disorders of hematopoiesis and neurological system . 
 there have been some reports of copper deficiency occurring to the patients on enteral nutrition through a jejunostomy in long - term - care hospitals . however , it is extremely rare to find patients with copper deficiency several months after esophagectomy , regardless of enteral nutrition through the jejunostomy . to the best of our knowledge , 
 this is the first case report of a patient who experienced copper - deficiency anemia after esophagectomy and subsequent enteral nutrition through the jejunostomy.presentation of casea 73-year - old man presented with pulmonary failure after esophagectomy for esophageal cancer with video - assisted thoracoscopic surgery , and needed long - term artificial ventilator support . 
 nutritional management included enteral nutrition through a jejunostomy from the early postoperative period . 
 copper - deficiency anemia was detected 3 months postoperatively ; therefore , copper supplementation with cocoa powder was performed , and both serum copper and hemoglobin levels subsequently recovered.discussioncopper-deficiency anemia has already been reported to occur in patients receiving enteral nutrition in long - term care hospitals . however , 
 this is the first case report of copper deficiency after esophagectomy despite administration of standard enteral nutrition through the jejunostomy for several months.conclusionit is extremely rare to find copper - deficiency anemia several months after esophagectomy followed by enteral nutrition through the jejunostomy . 
 however , if anemia of unknown origin occurs in such patients , copper - deficiency anemia must be considered among the differential diagnoses .