THE IMPORTANCE OF IMMUNOHISTOCHEMICAL STUDIES IN THE DIAGNOSIS OF CANCER OF UNKNOWN PRIMARY ORIGIN

The purpose of the research is to give a comparative diagnostic characteristic to tumors of unknown primary origin by admission diagnosis and morphological diagnosis. 162 treated cases with tumors of unknown primary at Oncologic Dispensary for 5 years were analyzed in details. Besides clinical, instrumental, cytological, morphological methods, immunnohistochemical research of tumors was carried out by avidin-biotin-peroxydase tecnics. The cases with poorly differentiated carcinoma (33,3±4,3%) and lymphoproliferative disorders (27,2±3,5%) prevailed among the cases with tumors of unknown primary by histological research. High degree of noncoincidence of cytologic and histological diagnoses (χ2=515, р=0,00001), histological and immunohistochemical diagnoses (χ2=378, р=0,00001), cytologic and immunohistochemical diagnoses (χ2=556, р=0,00001) were revealed. Cytologic overdiagnosis of undifferentiated carcinoma by 13,6% (р<0,05) and hypodiagnosis of benign diseases by 4,4% (р<0,05) and histological overdiagnosis of poorly differentiated carcinoma by 11,1% (р<0,05) and hypodiagnostics of tumors of nerve tissue by 8,0% (р<0,05) are marked, that points to the necessity of making immunohistochemical research in the cases of given pathology. Statistically significant connection of mean degree between diagnoses of poorly differentiated tumors made by cytologic, histological and immunohistochemical investigation is revealed.