it has been well known that about half of the patients with lung cancer have metastases at the time of initial diagnosis . the common sites of distant metastases are the bone , liver , adrenal glands , and lymph nodes . the clinical symptoms of the metastases of bone , liver , and lymph nodes usually occur relatively earlier . therefore , these metastases are often diagnosed at the same time the diagnosis of lung cancer was made . however , in the case of metastases to the kidneys , adrenal glands , gastrointestinal tract , and skin , the clinical symptoms of metastasis do not appear early and are usually found at postmortem examination . in particular , the intestinal metastases of primary lung cancer are hardly diagnosed until the development of intestinal obstruction , perforation or hemorrhage ; these cases usually show high mortality rate on operation . since morgan s first report in 1961 of small intestinal metastasis from lung cancer , 27 cases with the clinical symptoms of perforation , obstruction and/or hemorrhage have been reported . among them , only 1 case was intestinal hemorrhage . we here present a case of intestinal hemorrhage that progressed to intestinal perforation and caused by small intestinal metastasis of carcinoma of the lung , large cell type . a 31-year - old korean male patient was transferred to our hospital from a local hospital because of persistent melena of undetermined origin . four months ago , the patient visited the hospital with complaints of chest tightness and productive cough . an x - ray film of the chest at that time showed a patch infiltration in the right lower lung field . studies of the sputum for acid fast bacilli were negative but anti - tuberculosis medications were started under the impression of pulmonary tuberculosis . three months later , he was admitted to the same hospital because of melena and underwent extensive work - ups including gastroscopic examination , barium studies of the colon and small bowels , and a gastric mucosa scan for meckel s diverticulum , but no bleeding focus was found . during the stay in that hospital , he did fairly well until 10 days prior to this admission when recurrent melena developed . additional studies including 99mtc - sulfur colloid scintigraphy were carried out , but no bleeding focus was found . on admission , the patient appeared pale and acutely ill . the blood pressure was 130/70 mm / hg , pulse rate 120/min , respiratory rate 20/min , and the temperature 36.5c . the urea nitrogen was 22.4 mg / dl , the creatinine 1.5 mg / dl , the protein 2.5 g / dl ( the albumin 1.3 g / dl and the globulin 1.2 g / dl ) , the bilirubin 0.4 mg / dl , the alkaline phosphatase 53 iu , the aspartate aminotransferase ( ast ) 10 iu , and the alanine aminotransferase ( alt ) 10 iu . chest x - ray film revealed an ill defined dense infiltrate with air bronchogram in the right lower lung field ( fig . however , a large amount of hematochezia persisted even after the operation and signs of serious disseminated intravascular coagulopathy ( dic ) follwed . on the 10th hospital day while the dic improved , on operation , multiple polypoid masses of various sizes were palpated intraluminally in the jejunum from 10 cm below the treitz ligament to the 120 cm distally . a large perforation of the jejunum ( 8 cm in diameter ) probably caused by necrosis of the bowel wall was found on the antemesenteric border of the jejunum 2025 cm below the treitz ligament . multiple mass lesions including hematomes were also found in the mesenteric root of the small intestine . small bowel resection and end - to - end anastomosis were performed . on section , 36 polypoid masses were scattered grossly along the full length of the resected jejunum . the cells in the polypoid mass lesion were consistent with large round cells of undetermined origin . bronchoscopic examination , which was done on the 10th postoperative day , revealed an obstructing round mass at the entrance of the right main bronchus ( fig . 5 ) . histologically , this lesion was diagnosed as large cell carcinoma of the lung ( fig . it has been reported that 41% of all patients with lung cancer are found to have evidence of distant metastases at the time of initial diagnosis , but the clinical symptoms of the metastases to the gastrointestinal tract are rarely present . the distant metastases of lung cancer are usually found at the lymph nodes , brain , bone , adrenal glands , and liver through lymphatic spread . mcneill et al . reported that primary lung cancer metastases to the small intestine was mainly from large - cell type carcinoma as our case . the peak incidence was in the sixth and seventh decade , similar to those of patients with primary lung cancer . most of the metastatic small intestinal tumors originated from the cervix , skin , ovaries , and kidneys . the clinical symptoms were usually those of bowel obstruction , perforation or rarely hemorrhage . by reviewing the literature of the 27 cases reported , 18 had intestinal perforation , 8 had obstruction and only 1 had hemorrhage(table 1 ) . postmortem examinations of 431 lung cancer patients studied over an 11-year period(1 ) showed that 46 patients ( 11% ) had metastases to the small intestine . among the 46 patients who received exploratory laparotomy with the symptoms and signs of intestinal obstruction or perforation , all of these 6 patients died within 16 weeks after the operation . on the other hand , according to the report of arianha et al . , 10% of patients with suspected metastasis were found to have benign lesions as the cause of small bowel obstruction . also , in the other 2 reports , 25% and 38% of patients with a history of cancer who underwent exploratory laparotomy because of intestinal obstruction were found to have either a benign disease or a new primary cancer as the cause of the obstruction . according to the report by woods iv et al , 8 out of 13 patients who underwent emergency exploratory laparotomy experienced successful palliation by surgical intervention . these data suggested that the cancer patients with intestinal obstrcution who do not have a proven abdominal cancer should undergo exploratory laparotomy . report a case of perforation caused by metastatic cancer after chemotherapy and they suggested that there might be a close relationship between the chemotherapy and perforation . inalsingh et al . also explained that local factors , such as trauma and/or irradiation , which could influence the immune response were related to the metastases . among 17 cases with intestinal perforation , 7 presented with perfortion after chemotherapy and radiotherapy . in conclusion , with increasing use of chemotherapy and radiotherapy for the treatment of cancer , the possibility of perforation of the small intestine from the metastatic tumor should be considered more carefully than before .