To compare the diagnostic accuracy of FNAC with histopathology in benign and malignant breast lumps

Introduction

Breast lump is one of the commonest surgical problems encountered in female patients. A breast tumor is an abnormal mass of tissue in the breast as a result of neoplasia. The most common breast tumour is fibroadenoma which is a benign condition. Malignant masses include ductal cell carcinoma, lobular cell carcinoma. The method for diagnosis of breast masses involve “Triple Test” which consists of clinical examination, mammography and FNAC.1 Biopsy of the breast lump is considered the benchmark for the diagnosis of breast lump. The aim of conducting biopsy is to demonstrate a final diagnosis of breast mass prior to surgery. Biopsy of the breast lump is a minor surgical procedure done under local anaesthesia or general anaesthesia with post operative morbidity included. The main purpose of fine needle aspiration cytology (FNAC) of breast lump is to confirm cancer preoperatively and to avoid surgery in form of biopsy for specific benign conditions. The cost factor is also taken into the account, given the large volume of work generated by breast cancer screening. Our aim is to compare the diagnostic accuracy of fine needle aspiration cytology (FNAC) and with histopathological correlation in patients with detectable breast lesions.2

Materials and Methods

The study was conducted in the Department of Pathology from Aug 2019 to Aug 2021. During this period, 101 fine needle aspiration were performed for various breast lumps. Out of these, 51 patients underwent surgery and form the material of the study. The FNAC was carried out using 23 Gauge needle and 10 ml disposable syringe for aspirating the material from the breast lump. Three or four dry clean slides were used for preparing the smear. The slides were labelled with glass pencil and were air dried. The cytological smears were fixed in 95% alcohol and stained with Haematoxylin and Papanicolaous stains. The surgical specimens for histopathological examination were fixed in 10% formal saline. The grossing and the cut section findings were noted. Several sections were taken from appropriate sites for processing and paraffin embedding. The section from each block were cut in 04 micron thickness and stained with Haematoxylin and Eosin.

Results

A total of 101 fine needle aspirations on breast lump were performed over a period of two years in a tertiary care hospital. Out of the 101 FNACs, cytological diagnosis was correlated with histopathological diagnosis in 51 patients. Sex distribution included 50 female and 01 was male. The age of patients ranged from 10-70 yrs. In FNAC, 49 cases were labelled as benign and 02 cases were malignant (distribution of cases as per Table 2). Out of 51 surgical specimen which were reviewed with HPE, 47 were confirmed as benign. The distribution of histopathologcal diagnosis is as per Table 3. Out of the 51 cases, 35 patients had fibroadenoma, 01 patient had phylloid tumor, 01 tubular adenoma, 03 fibrocystic disease of breast, 04 patients had inflammatory or breast abscess, 01 patient had gynaecomastia and in 02 cases no opinion was given. Out of the 04 malignant cases in HPE, 01 patient had a diagnosis of ductal cell carcinoma and 03 patients infiltrating ductal carcinoma. Benign lesions involved patients in second & third decades of life. The malignant lesions were reported in fifth and seventh decades. The most common benign lesion was fibroadenoma with maximum incidence in second & third decades and followed by breast abscess and then fibrocystic disease of breast with maximum incidence in fourth decade. In the malignant cases, the most common was infiltrating ductal cell carcinoma with maximum incidence in fifth & sixth decades. The correlation between FNAC and histopathological examination for the sensitivity, specificity and positive predictive value were calculated. The false positives were zero and 02 were false negative cases in the study. The cytohistological correlation of 51 patients, out of which 04 patients has the final diagnosis of malignancy and 47 patients had benign condition. In the present study, the sensitivity of FNAC was 50%, specificity 100% and the positive predictive value of 100%, negative predictive value 95.9% and the overall accuracy of the study was 96.1%.

Figure 1

Cytological smear showing stag horn pattern with benign ductal epithelial cell in sheets & cluster with bare nuclei

Figure 2

Histopathological feature shows intracanalicular pattern of fibroadenoma

Figure 3

Atypical ductal epithelial cells are arranged in dyscohisive clusters with hyperchromatic nuclei, irregular nuclear membrane and prominent nucleoli

Figure 4

Infilterating tumor arranged in nests, cords and trabeculae. The tumor cell show moderate nuclear pleomorphism, coarse chromatin and moderate eosinophic cytoplasm

Discussion

Fine needle aspiration cytology is performed as the first investigation in breast lumps for screening in both symptomatic and asymptomatic population. The risk factors for breast cancer include female sex, obesity, lack of exercise, hormone replacement therapy during menopause, alcoholism and ionising therapy. In our study, 101 aspirations were performed in a duration of two years. 50 cases were not followed up due to lack of surgical specimen for HPE. 51 cases of FNAC which had excised surgical specimen in form of lumpectomy or definitive surgery depending on diagnosis on aspiration cytology for HPE were included in the study. The aspiration cytology was correlated with the histology report to see accuracy of fine needle aspiration cytology with open biopsy/Lumpectomy HPE specimen. The results were tabulated and conclusion drawn based on statistical study.

Pinto et al. carried out 58 FNACs of breast with subsequent histopatholgy, the youngest patient was 12 years old & the oldest patient was 82 years old. In their study fiboadenoma was the most common benign lesion in female and gynecomatsia was the most common lesion in male.3 In the present study, our observation is similar, the fibroadenoma being common in female (68.7%) and gynecomastia being common in male.

K Pailoor studied 40 male patients and out of which 8 cases had cyto-histopathological correlation. The diagnostic accuracy of gynecomastia was 100% in histopathology.4 In our study similar result were found.

In another study by Tiwari M, 21 cases of histopathological correlation, the commonest cause of breast lump was fibroadenoma accounting (39.5%) of total cases and Invasive/infilterating ductal carcinoma being 6.6%. All cases of malignancy in FNAC proved to be malignant lesion by biopsy. In one case, FNAC showed only inflammatory & necrotic material, which was later proved to be malignant by biopsy.5 Similar results were found in our study as well. Our study showed that the commonest breast lump is fibroadenoma (68.7%) between the age group of 20-40 years. Between the age group of 50-70years, 04 cases (7.8%) of breast malignancy were found & the common malignancy in breast being infiltrating /invasive ductal cell carcinoma. Further, two cases in FNAC showed fibrocystic disease of breast which turned out to be malignant in the biopsy.

In another study done by Yalavarti S, 56 patients were studied with cytopathological correlation, of which benign lesion, 45% were reported in third decade and the maximum number of malignant lesion 44% were reported in fifth decade.6 Our studied shows benign lesions 92% reported in second to third decade and the malignant lesion 08% were reported in fifth to sixth decade

Many authors suggest different reporting protocols in classifying the breast lesions. In one of the study done by Ishita classification of the lesions were into four groups i.e benign, malignant, suspicious and inadequate.7 In the present study, cytological diagnosis of 51 aspiration were evaluated and the lesions were classified into four classes, 49 as benign, 02 malignant, suspicious & inadequate being nil.

Another study done by Lopez-Ferrer on 362 cases of fibroadenoma showed Cyto-histological correlation in 287 cases out of 362 (79.28%) and lack of correlation was present in 75 cases.8 In the present study, the cyto-histological correlation was 68.7% for fibroadenoma and 5.9% for fibrocystic disease of breast. Out of 49 cases of benign condition, 35 cases were diagnosed histologically as fibroadenoma, three fibrocystic disease, one case of benign breast disease as phylloid tumor and another case of benign breast disease as tubular adenoma. In our study we failed to diagnose two cases of malignancy in FNAC.

In our study, two cases in FNAC show fibrocystic disease of breast turned out to be malignant in biopsy. Similar observations were found in study done by Hamed H, Coady et al. on 401 women presenting with breast lumps.9

Most of the breast lesions are benign and need reassurance to the patient to prevent anxiety and discomfort. Therefore FNAC is very highly accurate in diagnosing benign lesions and hence surgery can be avoided in such cases for HPE.10, 11 The findings of our study are supported by the literature. (Table 6)

Conclusion

Fine needle aspiration cytology is a comfortable, easy, reliable, rapid and simple diagnostic test. The FNAC of breast lump should be used with” triple test” for preliminary investigation in outdoor patient department, which will further enhance the diagnostic accuracy of breast lumps. The FNAC aspirate can be used for ancillary molecular testing also.

Source of Funding

None.

Conflict of Interest

The authors declare no conflict of interest.