The aim of the study was to compare the morphological features of lung cancers in paraffin and semithin sections. The analysed matirial was abtained durnig thoracotomy and bronchoscopic biopsies. The resected segments about 2 mm in diameter were preserved in3% glutaraldehyde. Then after rinsing they were moved to osmobuffer mixture and to cacodylic buffer. The material degytrated was in alcohol sequence from 50%-95%. Then after rinsing it in mixture of propylene oxide and eponthe material was embedded in epoxy resin. Then the obtained blocks were cut with an ultramicrotome into slides of 0,5-1 micron thick. The examined semithin sections were viewed on magnification 400x and 1000x at the light misroscope and compared with histopathological slides obtained by a routine paraffin method. The results of our research allow us to draw the following conclusion: the examination of semithin sections enables a more precise evaluation of the cell nucleus and cytoplasm, disclosing the number of nucleoli, translocations of nuclear chromatin and the onset of regressive changes in cytoplasm.

Keywords: lung cancer, morphological diagnosis, Technique