Introduction: Infíltrative type of basal cell carcinoma, known as "morpheaform basalioma" is an inva-sively growing type of malignant epithelial tumor. Tumor behavior is influenced also by the tumor basement membráně statě and by relation of tumor parenchyma to tumor stroma. In routine practice the histo-pathologists follow an empirical judgement of the hasement membráně using various visualization methods. In our páper we tried to statistically evaluate the validity of use of the most frequent visualiza-tion methods of basement membráně assessment in the histopathological practice. Materiál and methods: 10 morpheaform basaliomas samples of the bioptic register of The Institute of Fathological Anatomy of JLF UK in Martin were processed by Gomori impregnation method, PAS method and immunohistochemical detection of laminin. The basement membráně integrity was evaluated semi-quantitatively measuring each 5 visual fields in 400 fold magnification. The results were processed by standard statistical methods ušed in data of small numher of statistical untis. Results: The medián value 20.5 was the samé using PAS method and laminin detection, in comparison to the 14.5 value acquired if calculating the basement membráně status using Comori method. The extent of minimal to maximal values was the largest from 12 to 24 using detection of laminin, similarly, but with extent from 11 to 22 using Gomori method. PAS method had the smallest extent from 18 to 24 but in higher values. Conclusion: Efficacy of suitable diagnostic methods plays one of the most important roles in the process of diagnosis. The study warns that evaluation of the basement membráně integrity in morpheaform basa-lioma by a PAS method is only approximative. We consider the Gomori method the most sensitive method in assessment of the defects of the basement membráně integrity. Immunohistochemical detection of laminin allows evaluating a qualitative precursor statě with identification of its local production loss in some tumor cells in the morpheaform basalioma

        Key words: morpheaform caninoma - basement membráně - laminin