Breast cancer (BC) is the most prevalent cancer in the world among women and there are nearly 1.7 million new cases worldwide each year. Due to a number of remarkable advances made in both diagnosis and therapy, the survival rates for BC patients have increased in those regions with adequate medical facilities. According to contemporary recommendations, any pathological diagnosis of breast lesions, before any treatment, should be based on a Core Needle Biopsy (CNB), or on a Fine Needle Aspiration Cytology (FNAC), if CNB is not available. The prognosis of the newly diagnosed breast cancer patient depends on a number of factors, among which the most important is the extent of the spread of the disease to the axillary lymph nodes. Because any further treatment is influenced by the presence and number of axillary lymph nodes involved, a complete evaluation of the axillary lymph nodes is performed on every patient that is able to tolerate it, after a formal diagnosis of invasive carcinoma. At the very least an ultrasound with guided fine needle aspiration or core biopsy of suspicious lymph nodes should be undertaken.Although CNB is the main method employed in breast lesions diagnostics, FNAC still plays a significant role in the evaluation of pathological processes in the breast, a fact that has been well documented in the relevant literature in the last 20 years. The advantages of FNAC are: the sampling is quicker; the sampling technique usually does not require the use of anaesthetics; the trauma is small, and therefore more convenient for women using anticoagulant therapy; complications are rare; the availability of the results is within a few hours; skilled operators and pathologists regard this method as being highly sensitive in the detection of any malignant cells and the equipment is less expensive. The United Kingdom National Health Service Breast Screening Program (UK NHSBSP), began in 1988. Its guidelines have been published with regards to the mode of categorizing cell changes that may be seen in cytological samples obtained by needle aspiration. Five categories have been identified: C1 (unsatisfactory specimen - non-representative), C2 (benign), C3 (atypical - most likely benign), C4 (suspected - most likely malignant) and C5 (malignant). In 1996, the American National Cancer Institute (NCI) also suggested 5 categories for cytological diagnostics of breast lesions: benign, atypical, suspected, malignant and unsatisfactory. Patients with C3 and C4 categories, namely, atypical and suspected, which carry the risk of a malignant tumour, need to undergo further examination. C1 and C2 categories have to be correlated with the results of clinical and radiological examinations. C3 and C4 categories should not be represented in more than 5% of all analyzed aspirates. Currently, there is no individual morphological criterion that cytological diagnostics of malignant breast tumours could be based on. The most important cytological criteria that indicate whether it is a benign pathological process or a malignant tumor are: cellularity of the sample (a very important criterion, but it should be carefully interpreted), loss of cell cohesiveness (characteristic of malignant tumors), cellular arrangements, cell size, biphasicity in smear, the characteristics of the nucleus (size, contour, the appearance of chromatin, the appearance of nucleolus), characteristics of cytoplasm, nuclear-cytoplasmic ratio, APSTRAKTI 93 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. mitotic figures, background appearance (necrosis, peripheral blood cells, mucus…) and the presence of inflammatory cells. It is also possible to perform immuno-histochemical staining on cytological samples, flow cytometry and molecular analyses. The FNAC treatment is characterised by solid sensitivity, specificity and predictive value. The sensitivity of FNAC ranges from 89% to 98% and the specificity is between 98% and 100%. Major shortcomings of this method are the impossibility of diagnosing in situ carcinoma and lesions followed by any abundant production of connective tissue. The CNB treatment has gained remarkable popularity since the 1980s and in many institutions has replaced FNAC. The limitations of both methods are; atypical ductal hyperplasia, fibroepithelial tumours, radial scarring and papillary lesions. In the diagnosis of breast lesions apart from aspiration cytology, other sampling techniques for cytological analysis are also applied. In the era of breast conservation therapy, breast tissue is most commonly sent for intraoperative consultation. A frozen section analysis is performed through freezing and sectioning the surgical specimen with subsequent staining, in order to obtain an extemporaneous assessment of the margins. Although this technique is extensively used by many surgeons to avoid the need for a postponed rescission, some pitfalls have been reported, such as the occurrence of artefacts due to the freezing and thawing of the adipose tissue in the specimen. A different intraoperative method for margins evaluation is imprint cytology, which consists of pressing each of the 6 faces of the specimen on 6 different slides, so that any malignant cell on any involved margin is theoretically present on the cytology of the respective slide, because of the tendency of tumour cells to adhere to glass as compared to adipocytes. Imprint cytology can also be used in assessing the representational value of the CNB samples. A significant number of authors suggest that the application of the imprint of cytology reduces the number of inadequate samples obtained by CNB and can also provide a preliminary diagnosis, especially in cases of adequately sampled malignant tumours. Nipple discharge (ND) accounts for approximately 5% of the breast-related symptoms and is the third most common reason women seek medical attention. Approximately 7% to 15% of unilateral NDs are caused by malignant lesions, primarily ductal carcinoma in-situ (DCIS). A cytological examination of the obtained content is significant in the final treatment decision. Cytological analysis, in particular FNAC, continues to play an important role in the diagnoses of breast cancer. Skilled professionals can determine breast cancer through an analysis of the cytological sample as a reliable and accurate method.

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