Cytological evaluation of breast lesion and its histopathological correlation in a tertiary care center

Background Breast cancer is one of the commonest cancers in female. FNAC is safe and cost affective screening test for breast lump having both high sensitivity and specificity. Our aim is evaluation of diagnostic accuracy of fine needle aspiration cytology [FNAC] in diagnosis of breast lesions. Material and Methods All male and female patients with breast lesion were subjected to cytological evaluation of which many were followed up with histopathological evaluation to assess the diagnostic accuracy of FNAC. Results Out of 1088 cases diagnosed on FNAC, 703 cases (64.61%) were benign and 232 cases (21.3%) were found to be malignant. In our study the most common benign lesion was fibroadenoma and commonest malignant lesion was Duct carcinoma. Maximum cases of breast lesions in females were in the age group of 2130 years followed by age group of 3140 years. While maximum cases in males were in the age group of 31-40 years & 6170 years. The sensitivity and specificity of FNAC for cyto-histo correlation were found to be 97.16% and 92.83% respectively. Conclusion FNAC is a highly sensitive and specific test for diagnosis and categorization of breast lesions into different categories of neoplastic and non-neoplastic breast lesions.


Introduction
World over FNAC has become widely accepted tool for diagnosis of breast lesions as it is safe and simple method with high diagnostic accuracy [1].Its success is due to its accuracy and cost effectiveness and high accuracy for a breast lump.Therefore, it holds to have many advantages for patients and surgeons [2].There are wide varieties of breast pathologies.It is postulated that the non-proliferative and inflammatory breast lesions do not increase the risk of cancer.There is mild to moderate risk with proliferative breast disease not showing atypia and with atypia respectively and higher risk of malignancy with carcinoma in situ [3].The success rate of FNAC for obtaining a definite diagnosis depends on whether the lesion is palpable and also its size.FNAC has approximately success rates of 75-90% for palpable and 35-55% for non-palpable breast lesions respectively [4].The use of core biopsy can be considered as an alternative but the procedure is more cumbersome, expensive and time consuming as compared to FNA procedure [5][6].The present study supported FNAC as a first line of investigation in work-up of breast lesion.In the present study our aim is to categorize the types of various breast lesions on cytology, to determine the adequacy rate, diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values of FNA in the evaluation of breast lumps.Cytologyhistopathology correlation was also seen for better insight of breast lesions.

Material and Methods
Various techniques for obtaining specimen for cytology are: Fine Needle Aspiration (FNA) technique, Fine Needle Capillary (FNC) sampling, Smears from nipple discharge, Scrape smears from ulcerated lesions and Cyst fluid of the patients.The study was carried for a period of two years, from 5 th June 2015 to 20 th June 2017.Equipment required for this purpose are Needles-23-22 gauge, Syringes and syringe holder -Cameco Syringe Pistol with 10 cc plastic syringe, Sterile containers, Slides -clean, dry and free of grease, fixatives-Coplin jar containing 95% ethanol and Stains-May Grunwald Giemsa (MGG), and Papanicolaou stains.The study was carried after getting the approval from institutional review committee.The data was analyzed by SPSS 14.0.

Results
The present study is an observational study that includes all breast lesions, observational analysis of1088patients were subjected to cytological evaluation,1061 cases were female and 27cases were male.The microscopic description of the sample and the diagnostic categories used for the smear listed below, as per recommendation with further specific sub-categorization whenever possible.Benign: when there is no evidence of malignancy with further description and classification.e.g.Finding below shows the Nature of specimen along with sample procured under USGguidance.

Sub-categorization of Benign Breast Lesion
In inflammatory lesions -Acute mastitis top the list followed by Chronic mastitisand nonspecific granulomatous mastitis.group Proliferative breast disease with atypia top the list with 34 cases followed by papillary lesion (8cases).In case of Suspicious / Probably malignant lesion, Atypical ductal hyperplasiatops the list followed by Low grade ductal malignancy.In malignant lesion maximum no. of cases was from ductal carcinoma (214 cases, including ductal malignancy with lymph node metastasis) followed by lobular carcinoma (11 cases).
In present study follow up biopsies with cyto-histopathology correlation was available in 215 cases.

Discussion
The objective of this study was to categorize and type the various breast lesions on cytology, statistically analyze the findings and correlate the cytology findings with histopathology for better insight of breast lesions on cytology.The most common cancer in Nepal is cervix carcinoma followed by breast carcinoma.[7,8,9].Different studies have shown that most commonly the lesions are benign for which only assurance is needed [8.9].In order to prevent the cancer and for accurate approach to treatment, it is important to screen and diagnose the breast lesions early and categorization them into different groups of breast pathology [10,11].Majority of breast lumps (55.05%) were located in the upper and outer quadrant of breast [12].The commonest benign breast lesion is Fibroadenoma.Ferguson also reported that

Conclusion
The FNAC of breast is cheap, safe and highly accurate investigation for diagnosis of breast lesions.The correlation between cytology and histology showed that FNAC is an accurate test in diagnosing and managing benign breast lesions.

Table 1 :
Categorization of breast lesions on cytology

Table 2 :
Distribution of Patients based on different methods of cytology.

Table 6 :
Atypical breast lesion with mild to moderate risk of cancer.