Objective: to estimate the accuracy of rapid intraoperative morphological diagnosis (RIMD) and to analyze reasons for diagnostic errors. Subjects and methods. In 2013, a total of 418 and 1198 emergency histological and cytological examinations were made in 361 (7%) and 646 (12.5%) patients, respectively. In 2014, there were 507 and 1356 emergency histological and cytological examinations in 356 (8%) and 676 (15.5%), respectively. The emergency histological examination used frozen sections stained with hematoxylin and eosin. A Leukodif kit (Czechia) was employed for rapid staining of cytological specimens. Immunofluorescence assay (IFA) using an anti-epithelial Ber-EP4 FITC antigen antibody («Daco») was carried out to examine exudates from serous cavities and to diagnose lymph node metastases. IFA was done using a Carl Zeiss Imager M1 fluorescence microscope. Results. The sensitivity and specificity of the histological method in RIMD were 98 and 99%, respectively; those of the cytological method in RIMD were 95 and 96%, respectively. The histological hyperdiagnosis and hypodiagnosis during emergency examination were 0.5 and 1%, respectively; the cytological ones were 3 and 9%, respectively. The presumptive conclusion rates for emergency histological and cytological examinations were 2 and 11%, respectively. 12% of the results of an intraoperative morphological examination of resection margin tissue samples show that it is necessary to extend surgical intervention. The non-informative material during an emergency examination is 2—5%, mainly during an emergency cytological one. Conclusion. RIMD remains indispensable for oncology since it can specify information on the pattern of a pathological process, the degree of its extent, and the state of the surrounding tissues and resection margins, which is essential in choosing an adequate surgical intervention. A complex cytological and histological examination is a gold standard for morphological analysis. An interdisciplinary approach incorporating the results of clinical and instrumental studies is required to achieve an accurate diagnosis.
