AIMS: To estimate potentialities of cytological diagnostics of different types of lobular carcinomas of the breast while outpatient examination.
 MATERIALS AND METHODS: The data of cytological investigations of 444 patients with carcinoma, which were detected by fine-needle aspiration biopsy, were studied. Traditional cytological diagnostics, as well as the liquid-based technique of preparation of patterns were used, staining of patterns according to the Pappenheim and Papanicolaou methods. A standard protocol for immunocytochemical reactions was used.
 RESULTS: Lobular carcinoma was detected in 15 patients. Types of lobular carcinomas were verified by cytological method were retrospectively identified.
 Classical, solid and tubular types of lobular carcinoma (n=7,46.7%; n=5,33.3%; n=1,6.7%) differed from unspecified breast carcinomas. In the classical type, vacuoles with a target-like inclusion (probably a drop of mucin) were a significant feature. In the solid type, the absence of complexes with a large number of separately located similar tumor cells was noticed. The tubular type was distinguished by the presence of tubular structures. The liquid-based technique helps to differentiate lobular and unspecified carcinoma using an immunocytochemical reaction with E-cadherin.
 CONCLUSION: The results of the study indicate that lobular carcinomas of the breast are 3.4% of all breast carcinomas. Taking into consideration the differences in prognosis, it is important to differentiate between lobular and unspecified ductal carcinoma at the outpatient level of diagnostics, as this is deciding for treatment strategy choice.