he reported chronic non - productive cough , weakness for the preceding three weeks , loss of appetite , and weight loss of about ten kilograms in six months . the interview and the medical history documentation indicated that he was suffering from diabetes type 2 , paroxysmal atrial fibrillation , hypertension , chronic renal failure grade 3 , and from generalised atherosclerosis . at age 45 it was located in segment 6 of the right lung , with diameter of 4.5 cm and lysis in the centre . in addition , the ct revealed in the enlarged lower pulmonary vein and in left atrium of the heart an hourglass - shaped structure with dimensions 5.4  1.6 cm . the results of laboratory tests of serum revealed the elevation of d - dimers ( 791 ng / ml ) and c - reactive protein concentration ( 37 mg / l ) . in bronchofiberoscopy the additional longitudinal echo ranging from right pulmonary vein ostia to the mouth of mitral valve was recorded b ) the loss of contrast in the left atrium and thickening of the pulmonary vein . after cardiothoracic consultation the patient was qualified for surgery . in the first stage sternotomy with extracorporeal circulation was performed . we incised the left heart atrium and revealed a pale pink tumour , which we removed completely from the atrium and from the final section of the right lower pulmonary vein . in intraoperative cytology of the tumour imprints the pathologist found non - small cell lung carcinoma cells . we decided to perform a right - sided thoracotomy in the second stage with right lower lung lobectomy and mediastinal lymphadenectomy . 2c the incised right pulmonary vein is shown with its wall infiltration forming the beginning section of the cardiovascular part of the tumour . a ) intracardiac part of the tumour just before the resection and ( b ) just after the resection . c ) right lower lobe  the pulmonary vein is cut and the infiltration of the vein wall is shown . in the final examination of the tumour the pathologist diagnosed mixed heterogeneous lung cancer ( squamous cell and non - small cell endocrine ) in stage iiia . there are very few cases of lung cancer extension via the pulmonary vein into the left atrium of the heart [ 2 , 3 ] . they can be diagnosed by use of transoesophageal echocardiograms , magnetic resonance imaging , and ct scan [ 1 , 3 ] . most of those tumours show rapid growth and comprise a large mass in the lung parenchyma . resection of the intra - atrial mass seems to be a life - threatening procedure because the patient may die from cardiac inflow obstruction and sudden cardiac arrest or massive tumour embolism involving the major organs [ 2 , 4 , 5 ] . the possibility of systemic tumour embolisation should be considered in patients with large , central tumours and particularly those that abut the pulmonary veins [ 4 , 5 ] . computed tomography with contrast allows the detection of the spread of lung cancer through the vessels into the heart cavity . malignant lung tumours penetrating into the cavity of the heart can be , in some cases , radically removed . in this case , the tumour did not infiltrate the left atrium of the heart but only grew into its light through the lower pulmonary vein ( iiia  t3n1m0  stage ) . the rapid progression of the tumour in the presented case ( the floating part of the tumour in the atrium grew 1 cm in a week , as seen by comparing ultrasound examinations of the heart ) rapid multidisciplinary collaboration of the two centres enabled fast and efficient qualification procedure .