there appears to be a 437% rate of complications and 26% mortality rate for those patients undergoing operative interventions for bowel obstruction .
one group of small bowel obstruction patients who present a clinical challenge are those who present with an obstruction due to intra - abdominal malignancy , a malignant small bowel obstruction ( mbo ) .
those patients present a clinical dilemma , as they are often nearing the end - of - life ; however , the intractable symptoms of pain , nausea and vomiting require management .
most frequently non  small - cell lung cancer metastizes into mediastinal lymph nodes , central nervous system , adrenal glands and liver .
. often such intestinal metastases present with ileus , perforation , intussusception or gastrointestinal ( gi ) bleeding .
a surgical resection of isolated lesion might be possible , however , a surgical treatment of disseminated disease is palliative with poor outcome .
we report an unusual case of acute small bowel obstruction due to metastatic occult lung cancer , which was diagnosed later after the emergency operation in the setting of postoperative diagnostics .
in this article we present an unusual case of a 53-year - old male patient , who was referred to our department because of acute intestinal obstruction , presumably of malignant cause .
otherwise the patient had a diabetes mellitus type 2 on peroral therapy , smoker for 30 years ( 15 cigarettes per day ) and occasional alcohol drinker .
prior to our treatment he was hospitalized at the internal clinic because of upper abdominal pain and vomiting .
he was dehydrated , laboratory tests showed hyperkalemia , mild leukocytosis and renal insufficiency , c - reactive protein was mildly elevated ( 27 mg / l ) .
the abdominal ultrasound showed dilated small bowel loops . computed tomography ( ct ) of the abdomen showed small bowel obstruction , but the exact cause could not be determined .
there were seen some changes of both adrenal glands , that were suspective for metastatic lesions ( fig .
figure 1:the abdominal computerized tomography showed small bowel obstruction with dilated small bowel loops ( arrow ) .
the abdominal computerized tomography showed small bowel obstruction with dilated small bowel loops ( arrow ) .
a small median laparotomy was made and a thorough exploration of abdominal cavity was performed . during the abdominal exploration we found multiple metastatic lesions along the entire length of small bowel and also some lesions along small bowel mesenterium .
one of the metastatic lesions was completely occluding the bowel lumen and was the cause of intestinal obstruction and ileus .
the other lesion along the entire length of small bowel were at that time nonobstructive .
we explored the entire abdominal cavity , but we did not find any other pathology , which would be suggestive as a primary tumor .
we took a sample of one metastatic lesion for definitive pathohistologic examination and then we created an intestinal bypass to relieve the intestinal obstruction .
we irrigated the abdominal cavity with saline and closed laparotomy with interrupted resorbable sutures without abdominal drain .
on the second postoperative day patient started with liquid diet , the nasogastric tube and foley catheter were removed , he started to pass stool spontaneously .
a few days after the patient was already discharged from the hospital , we received the pathohistological report , which has spoken for a metastasis of poorly differentiated adenocarcinoma . according to imunophenotype
it could be the metastasis from primary lung adenocarcinoma , less likely from stomach or tyroid gland adenocarcinoma ( fig .
figure 2:the chest computerized tomography scan showed a infiltrating tumor mass at the upper left lung ( arrow ) .
the chest computerized tomography scan showed a infiltrating tumor mass at the upper left lung ( arrow ) .
because of unknown origin of small intestinal metastases , the patient was referred to extensive diagnostics .
chest ct showed a large primary lung tumor in the left upper pulmonary lobe with pathological mediastinal lymph nodes .
the patient was presented to multidisciplinary team and was later referred to oncology for further treatment .
approximately half of lung cancer cases are inoperable at the time of diagnosis , due to metastases to various organs , including brain , liver , bones and adrenal glands .
such lesions are usually manifested by intestinal obstruction , perforation and rarely bleeding or peritonitis .
small bowel metastases from primary lung cancer are usually confirmed by pathological analysis with the help of immunohistochemical staining of ttf-1 , cdx2 , ck7 and ck20 , to differentiate the primary small bowel tumor from metastases of lung cancer .
metastases from a primary lung cancer to the gi tract are relatively rare with a frequency ranging from 0.2 to 1.7% in several studies .
however , autopsy data have suggested a much higher frequency of gi metastases of lung cancer than clinically reported cases and there in a prevalence of 4.714% .
this discordance between clinical and postmortem studies can be attributed to the fact that gi metastases from lung cancer very rarely give rise to symptoms or complications [ 6 , 7 ] .
haematogenous small bowel metastases of carcinoma of the airways seed more often in the ileocoecal region and are more often isolated , whereas small bowel metastases of intestinal tumors are smaller and show a more disseminated pattern of spread .
the ileum is supposed to be the most common site of metastasis from lung cancer , metastasis to jejunum occurs at a slightly lower prevalence in comparison to the ileum and metastasis to the duodenum in relatively rare .
interestingly , in our case we found a diffuse pattern of haematogenous spread to the small bowel from a primary lung cancer .
most patients with small bowel metastases have no specific symptoms such as anorexia , abdominal pain , distention and diarrhea . with the progression of disease
, life - threatening symptoms do present , such as small bowel obstruction , perforation and even bleeding . because of the difficulty in early detection of gi diseases , the diagnosis of small bowel metastases is often delayed before it is presented with life - threatening complications , which frequently requires an emergeny operation [ 5 , 6 ] .
the optimal treatment and management strategy for malignant bowel obstruction continues to be a widely debated topic .
evaluation for a definitive operation to remove or overcome an obstruction is the first step after the diagnosis .
surgical resection is indicated , when the tumor is localized , without extensive vascular invasion or metastases and the patient has good performance status .
the management of lung cancer patients presenting with symptomatic gi metastases remains controversial with some authors advocating conservative management with maximum comfort care due to the poor outcome . on the other hand
, others have recomended agressive surgery as it offers effective palliation . in our case ,
primary lung cancer was suspected by a pathologist according to the immunohistochemical staining of metastatic lesion , that was taken from small bowel mesenterium during surgery .
the diagnosis was later confirmed with chest ct , showing a large tumor mass in the left upper pulmonary lobe .
the second abdominal ct confirmed diffuse small bowel metastases , that were found during emergeny surgery and metastases to both adrenal glands ( stage iv ) .
improved awareness of gi tract metastases among physicians is important , since the incidence of lung cancer is increasing and patients with lung cancer now live longer due to improvement in treatment .
gastrointestinal metastasis as the initial presentation of primary lung cancer is relatively rare in the clinic .
surgical management should be considered as palliative treatment in patients with a bowel obstruction caused by primary lung cancer .
 abstractwe present a case of male patient , who was referred to our department because of acute intestinal obstruction , which was the initial clinical symptom of primary lung cancer . 
 the abdominal computed tomography ( ct ) prior to the emergency operation showed small intestinal obstruction and metastases to both adrenal glands . 
 the patient underwent an emergency abdominal exploratory laparotomy , that confirmed small bowel obstruction and diffuse metastatic lesions along the entire small bowel length . during the operation we took a sample of one metastasis for pathological examination and we created an intestinal bypass to relieve small bowel obstruction . the pathologist suspected to primary lung cancer according to the immunohistochemical staining . 
 the chest ct after the emergency operation showed a large primary tumor in the left upper pulmonary lobe . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONCLUSION
CONFLICT OF INTEREST STATEMENT