insight into molecular mechanisms has led to the development of promising therapeutic options , which improve the prognosis of affected patients . there are only a few reports on molecular tumour subtypes and clinical presentation of the disease . we present the case of a patient with anaplastic lymphoma kinase ( alk)-positive adenocarcinoma of the lung with an unusual metastatic pattern . the metastatic pattern of non - small cell lung cancer with alk translocation may be different from other lung cancers . an uncommon clinical presentation may sensitize treating physicians to perform corresponding molecular testing in order to offer the best treatment options . an otherwise healthy , 62-year - old , non - smoking caucasian woman had been complaining of postprandial , partly colicky epigastric pain for 2 months . she reported a weight loss of 1.5 kg over the past few weeks despite a normal appetite . a chest ct showed two masses , 23 and 9 mm in diameter , in the right upper lobe , and hilar lymphadenopathy . on bronchoscopy , no endoluminal tumour was seen ; however , cytology from the mediastinal lymph nodes was consistent with the same adenocarcinoma found in the stomach ( positivity for ttf-1 and cytokeratin 20 ) . magnetic resonance imaging of the brain revealed multiple , asymptomatic supra- and infratentorial metastases up to 22 mm in diameter . epidermal growth factor receptor mutation analysis on the gastric biopsy was negative for exons 1821 , but anaplastic lymphoma kinase ( alk ) rearrangement was positive on fluorescence in situ hybridization : an alk fusion transcript was detected in 55% of the tumour cells ( fig . 2 ) . treatment comprised whole - brain radiotherapy followed by platinum - based chemotherapy , resulting in stable disease and symptomatic improvement of abdominal pain . after 2 months , progression in the form of new liver metastases was noted on a ct scan , and the patient was enrolled in an expanded access program and treated with the alk inhibitor crizotinib . the patient 's tumour - associated symptoms ( i.e. anorexia and asthenia ) improved considerably within 2 weeks , and tumour response was seen on a ct scan and endoscopy ( fig . 3 ) after 6 weeks of treatment . to date , the patient is doing well with no evidence of progression after having been treated with crizotinib for 9 months . we present the unusual case of a patient with alk - positive adenocarcinoma of the lung who presented with a symptomatic gastric metastasis . there is an approximate 4% incidence of alk rearrangement in a certain non - small cell lung cancer ( nsclc ) population [ 1 , 2 , 3 , 4 , 5 ] . however , the incidence is significantly higher ( up to 22% ) in young , non - smoking patients with advanced tumour stage . the most common localisations of extrapulmonary metastases in lung cancer are the liver , bones , adrenal glands and brain . the incidence of metastases to the gastrointestinal tract has been reported to be as high as 11.9% for the entire gastrointestinal tract [ 7 , 8 , 9 ] and 1.75.1% for gastric metastases found on autopsy interestingly , the incidence of symptomatic gastrointestinal lesions is only 0.21.77% [ 7 , 13 , 14 ] . thus , gastric metastases either occur late during the course of the disease or are occult . a recent publication has demonstrated a correlation between the molecular oncogene status and the biological behaviour in nsclc , resulting in distinct metastatic patterns . a total of 209 patients with stage iv nsclc were assessed for alk rearrangement , epidermal growth factor receptor and v - ki - ras2 kirsten rat sarcoma viral oncogene homolog ( kras ) mutational status . compared to those patients with triple - negative tumours , the alk - positive patients showed a significant association with pleural , pericardial and liver metastases . of note , patients with alk gene rearrangement were found to have more metastatic sites affected at initial diagnosis when compared to those with triple - negative tumours , again indicating a different biological behaviour and metastatic pattern of this disease . these findings underpin our case , as gastric metastases are commonly indicative of a more advanced disease stage . although the prognostic significance of alk positivity currently remains unclear , these observations would assume a more aggressive natural disease course . to the best of our knowledge , clinical presentation with a symptomatic gastric metastasis in an alk - positive lung cancer patient has not been reported to date . this supports other observations that the metastatic pattern of this particular nsclc subtype is different from that of other lung cancers . apart from patient and tumour characteristics associated with the presence of an alk translocation ( i.e. never or former smoker , young age , adenocarcinoma and frequent liver , pleural and pericardial metastases ) , an uncommon clinical presentation may also sensitise treating physicians to the need to perform corresponding molecular testing in order to offer the best treatment option .
backgroundnon - small cell adenocarcinoma is a frequent tumour entity with a high mortality . 
 insight into molecular mechanisms has led to the development of promising therapeutic options , which improve the prognosis of affected patients . 
 there are only a few reports on molecular tumour subtypes and clinical presentation of the disease . 
 we present the case of a patient with anaplastic lymphoma kinase ( alk)-positive adenocarcinoma of the lung with an unusual metastatic pattern.conclusionthe metastatic pattern of non - small cell lung cancer with alk translocation may be different from other lung cancers . 
 an uncommon clinical presentation may sensitize treating physicians to perform corresponding molecular testing in order to offer the best treatment options .