the most frequent primary malignancy causing brain metastases is lung cancer , followed by breast cancer . most gastric cancer patients with metastasis develop cachexia with peritoneal carcinomatosis and usually die of multiple organ failure . single organ failure by metastasis is relatively uncommon as a cause of death , and brain metastasis itself rarely causes death . generally , the prognosis of patients with metastatic brain tumors is much poorer than that of patients with metastases in other organs , and the cases of metastases from gastric cancer are no exceptions . most patients who have metastatic brain lesions present with neurological symptoms during the course of their disease . we describe a 61-year - old korean woman with brain metastases from gastric carcinoma , presenting with polydipsia and polyuria , which is very rare . she was initially evaluated at another hospital for the possibility of diabetes mellitus , but laboratory data were not diagnostic for the disease . a physical examination showed her height to be 150 cm and body weight to be 50 kg . the laboratory tests on admission showed serum sodium at 152 meq / l , serum potassium at 4.1 meq / l , fasting blood glucose at 103 mg / dl , and hemoglobin a1c at 4.9% . the results of the liver and thyroid function tests , as well as the chest x - ray were all within normal limits . urine osmolarity , after a pitressin injection , was markedly increased ( > 50% ) and the results revealed complete pituitary diabetes insipidus ( table 1 ) . a brain mri was performed to demonstrate abnormal findings in the posterior pituitary gland , but it showed multiple enhanced nodules with surrounding edema in the entirety of the cerebral hemisphere , suggesting brain metastases ( figure 1 ) . to determine the origin of the brain metastasis , we performed the following diagnostic procedures : mammography , abdominal ct scan , gastroscopy , and bone scintigraphy . the abdominal ct scan showed a 3.5-cm heterogenous mass of the right adrenal gland , which separated the kidney . the mass was suggested grossly as metastases and no other intra - abdominal mass was seen there was no abnormal finding detected by mammography . two round - shaped , elevated lesions with central umblications were noticed on the antrum and low body of the stomach ( figure 2 ) . histologic examinations of both the gastric tissue and right adrenal mass showed malignant tumors composed of anaplastic cells ( figure 3 ) . smears and a cell block from the right adrenal mass showed pleomorphic cells having bizarre nuclei and abundant eosinophilic cytoplasm , which were strongly positive for vimentin and weakly positive for cytokeratin immunostains , but were negative for synaptophysin . thus , the right adrenal mass was suggested as a metastatic lesion from anaplastic carcinoma . the results of the immunohistochemical studies ( cytokeratin , vimentin , desmin , smooth muscle actin , alpha - fetoprotein , and human chorionic gonadotropin ) on the gastric tissues favored anaplastic carcinoma rather than sarcoma . the malignant cells of the adrenal mass were closely similar to the malignant cells from gastric tissues . using an electron microscopy examination , the tumor cells of the gastric tissues were composed of a mixture of round oval cells and pleomorphic cells ; and the tumor cells were occasionally joined by desmosome , which is suggested to be the origin of epithelial cells . however , there was no evidence of steroidogenic cells in the adrenal cortical carcinoma including in the well developed ser and mitochondria with tubular cisternae . the ultrastructural findings of the tumor cells were compatible with anaplastic carcinoma , including sarcomatoid carcinoma , rather than cortical carcinoma ( figure 4).therefore , the metastatic lesions of the brain and right adrenal gland were assumed to have originated from gastric carcinoma . she was managed with conservative treatment including desmopressin . after the desmopressin treatment , diabetes insipidus was greatly ameliorated . gastric carcinoma is one of the most common malignancies in korea , and most patients die from progressive cachexia . brain metastases from cancers of the gastrointestinal tract are uncommon , occurring in only 1.09.5% of all cases . in a review of autopsies involving carcinomas , intracranial metastases were found in 8.3 of 1000 cases of gastric cancer . at m.d . anderson , only 24 of 3320 patients with gastric cancer were found to have brain metastases during a 40-year period . in korea , kim reported the rate of incidence of intracranial metastases from gastric carcinoma is 0.16% . from a clinical perspective , brain metastases of gastric cancer have only been described in about 0.55% of cases . the most frequent primary malignancy causing brain metastases is lung cancer , followed by breast cancer . brain metastases from gastric cancer are unusual because the liver and lung act as barriers to the hematogenous spread of gastric cancer to the central nervous system . accordingly , metastatic lesions located elsewhere have usually been found before the manifestation of the brain metastases . the most common intracranial metastatic lesion of gastric cancer is meningeal carcinomatosis , while isolated metastasis to the encephalic parenchyma is rare . metastasis to the central nervous system from gastric cancer is mostly lymphogenous and occurs as meningioma , and metastasis to the cerebral parenchyma , which is generally thought to be via the arterial blood flow , is rare . according to a japanese report , the most common presenting symptoms of brain metastases are weakness ( 67% ) , headache ( 42% ) , balance / gait abnormalities ( 42% ) , and nausea / emesis ( 38% ) . less common findings are papilledema ( 13% ) and seizures ( 8% ) . according to kim s report in korea , patients with brain metastases present with headache , nausea , vomiting , cerebellar dysfunction , or other focal neurological deficits as the manifestations of parenchymal metastases . but in the current case , the patient presented with polydipsia and polyuria without a headache and other neurological symptoms . we initially thought that she had central diabetes insipidus , and there was the possibility of breast cancer as the primary lesion . many patients die soon after diagnosis , or they suddenly lose consciousness and are alternately found to have metastases by autopsy . the patient of the current study died of complications related to tumor progression 3 months after the diagnosis of the disease . in patients with brain metastases from gastric carcinoma , it appears that no currently available treatment regimen is likely to produce long - term survival or yield an improved neurological status . in a review of studies about the efficacy of the treatment in metastatic gastric carcinoma , although a selection bias of surgical candidates obscured the true value of the surgical resection of a metastatic lesion , their recommendation is likely to be the best palliation when the condition of the patient is favorable to surgery . in other korean studies , neither chemotherapy nor radiation directed at the intracranial metastatic lesion altered the clinical course . the patient of the current study did not receive a specific treatment for the brain lesions , except for a desmopressin treatment . in this case , we used an em examination to find the origin of the brain metastases , and found that the tumor cells of the gastric tissues were composed of a mixture of round oval cells and spindle cells . however , there was no evidence of steroidogenic cells in the adrenal cortical carcinoma including in the well - developed ser and mitochondria with tubular cisternae . the ultrastructural findings of the tumor cells were compatible with anaplastic carcinoma , including sarcomatoid carcinoma , rather than cortical carcinoma . finally , we conclude that the multiple metastatic brain lesion and right adrenal tumor were assumed to have originated from gastric carcinoma . this case report is presented to make clinicians aware of the possibility that diabetes insipidus ( polydipsia and polyuria ) may present as an initial manifestation of brain metastases of gastric carcinoma .
metastatic brain tumors from gastric cancer are extremely rare . 
 a 61-year - old korean woman , initially presenting with polydipsia and polyuria , was found to have metastatic lesions in the brain by mri . 
 we performed several diagnostic procedures to determine the origin of the brain metastases . 
 she was revealed to have a soft tissue mass of the right adrenal gland and fungating ulcers in the stomach . 
 histologic studies of both the adrenal gland mass and gastric tissues revealed malignant tumors composed of anaplastic cells . based on the electron microscopy study , 
 the malignant tumor of the right adrenal gland was a metastatic lesion from the anaplastic carcinoma of stomach . 
 therefore , the malignant tumors of the brain were assumed to have originated from the gastric cancer.this case report is presented to make clinicians aware of the possibility that diabetes insipidus ( polydipsia ) may present as an initial manifestation of brain metastases .