Study of Fine Needle Aspiration Cytology of Breast Lump : Correlation of Cytologically Malignant Cases with Their Histological Findings

Background: In Bangladesh a large number of patients have been suffering from breast cancer and with each passing year, the number is increasing. Objectives: To correlate breast lesions diagnosed as cytologically malignant with their histological findings. Methods: This is a prospective study carried out in the Department of Pathology, BSMMU, Dhaka during the period of January 2009 to December 2009. Patients with breast lump, having malignant breast lesions on cytology were included in the study. A total of 524 patients with breast lump underwent FNA examination for the diagnosis during this period. FNA slides were examined under light microscope after Papanicolaou staining and were categorized into five groups: i) inadequate ii) benign iii) atypical cells iv) suspicious for malignancy and v) malignant. Of these, 431 were diagnosed as benign, 4 as atypical, 17 were diagnosed as suspicious for malignancy and 72 cases were diagnosed as malignant. Out of these 72 cases, which were cytologically diagnosed as malignant, 55 corresponding surgical specimens (either mastectomy or lumpectomy specimens) were received for histopathology. The sections were stained with haematoxylin and eosin for microscopic examination. Results: 55 cases which were diagnosed as malignant by FNAC were found to be malignant by histopathology. 54 (98.18%) were invasive ductal carcinoma (NOS) and one (1.82%) was mucinous carcinoma. In this study, considering only cases with a definitive diagnosis of malignancy, the sensitivity of FNAC to diagnose the disease was 100% and accuracy was 100% and Chi-square test revealed Chi-square value 10.83 (P< 0.001). Conclusion: From the present study it is evident that FNAC is a simple and reliable method. No local anaesthesia is required. Operative risk of surgical biopsy, danger of post operative infection can be avoided by adopting the procedure. It helps to confirm the clinical impression without open biopsy.


Introduction:
In Bangladesh, patients suffering from breast cancer have been increasing.Because of the existing social circumstances, the tendency to overlook the complaints, and because female patients are hesitant to be examined by the clinicians for lump in the breast, they report in advanced stage of breast cancer 1 .FNAC of breast lump can be effectively used as a diagnostic tool in the diagnosis and management of breast lump on an outpatient basis as hospitalization of the patient is not necessary.Fine needle aspiration cytology (FNAC) of breast is an important part of the triple assessment of palpable breast lump (clinical examination, imaging [mammography or ultrasonography], and FNAC).It has been shown that FNAC can reduce the number of open biopsies 2 .The most common sign and symptom of breast disease is a palpable mass; although breast diseases can also present as inflammatory lesion, nipple secretion or imaging abnormalities 3 .

Abstract:
Background: In Bangladesh a large number of patients have been suffering from breast cancer and with each passing year, the number is increasing.Objectives: To correlate breast lesions diagnosed as cytologically malignant with their histological findings.Methods: This is a prospective study carried out in the Department of Pathology, BSMMU, Dhaka during the period of January 2009 to December 2009.Patients with breast lump, having malignant breast lesions on cytology were included in the study.A total of 524 patients with breast lump underwent FNA examination for the diagnosis during this period.FNA slides were examined under light microscope after Papanicolaou staining and were categorized into five groups: i) inadequate ii) benign iii) atypical cells iv) suspicious for malignancy and v) malignant.Of these, 431 were diagnosed as benign, 4 as atypical, 17 were diagnosed as suspicious for malignancy and 72 cases were diagnosed as malignant.Out of these 72 cases, which were cytologically diagnosed as malignant, 55 corresponding surgical specimens (either mastectomy or lumpectomy specimens) were received for histopathology.The sections were stained with haematoxylin and eosin for microscopic examination.Results: 55 cases which were diagnosed as malignant by FNAC were found to be malignant by histopathology.54 (98.18%) were invasive ductal carcinoma (NOS) and one (1.82%) was mucinous carcinoma.In this study, considering only cases with a definitive diagnosis of malignancy, the sensitivity of FNAC to diagnose the disease was 100% and accuracy was 100% and Chi-square test revealed Chi-square value 10.83 (P< 0.001).Conclusion: From the present study it is evident that FNAC is a simple and reliable method.No local anaesthesia is required.Operative risk of surgical biopsy, danger of post operative infection can be avoided by adopting the procedure.It helps to confirm the clinical impression without open biopsy.Key words: Breast lump; FNAC; Mastectomy; Malignancy.

[BSMMU J 2011; 4(2):60-64]
Address of correspondence: Dr. Touhid Uddin Rupom, Lecturer, Department of Pathology, National Institute of Cancer Research and Hospital (NICRH), Mohakhali, Dhaka, Email: touhidrupom@yahoo.comFNAC is now used more frequently to diagnose any mass in the breast, which is clinically malignant.It is extremely beneficial in reaffirming the clinical impression of benign disease, which may not need subsequent biopsy.Furthermore, it allows more rapid diagnosis of a malignant condition in clinically non-suspicious masses.The ultimate benefit of aspiration cytology, however, rests in its demonstration of malignant disease, when other diagnostic modalities are inconclusive 4 .FNAC is now a well established tool for the investigation of women with suspected breast carcinoma 5 .A cytodiagnosis based on the examination of smears prepared from the aspirate can accurately predict the histology of the tumour in about 90% of cases 6 .
It has improved decision making and the selection of patients for biopsy of breast lesion and has contributed in saving time in the clinical management of breast disease 7 .Advantage is that when the cytological diagnosis is a malignant lesion, the nature of the condition can be discussed with the patient and a full explanation of the proposed operation, length of stay in hospital and after care can be given 8 .
The present study is designed to correlate findings of cytologically malignant breast lesions of patients attending outpatient department, with their histomorphologic findings.

Methods:
It was a prospective type of study carried out in the Department of Pathology, BSMMU, Dhaka, during the period of January 2009 to December 2009 and the study was approved by the departmental ethical committee.Patients with breast lump, initially diagnosed as malignant on FNA cytology were included in the study.A total of 524 patients with breast lump underwent FNA examination for evaluation during this period.FNA slides were examined under light microscope after Papanicolaou staining and were categorized into five groups: i) inadequate ii) benign iii) atypical cells iv) suspicious for malignancy and v) malignant.Of these, 431 were diagnosed as benign, 4 as atypical, 17 were diagnosed as suspicious for malignancy and 72 cases were diagnosed as malignant and were graded by Robinson's Cytology Grading System.Out of these 72 cases, cytologically diagnosed as malignant, 55 corresponding surgical specimens (either mastectomy or lumpectomy specimens) were received for histopathological examination subsequently.Specimens were fixed in 10% formalin solution, routinely processed, sectioned and stained with hematoxylin and eosin staining methods for microscopic examination and were graded by Bloom Richardson Scoring System.Cytological findings of malignant cases were correlated with their histologic findings.Sensitivity and accuracy of diagnosis were calculated using Chi-square test.

Results:
The age range of total 55 patients was 20-80 years with the mean age of 43.2 years.Highest frequency of malignant breast lump was found in the age group of 36-45 years.Out of 55 patients, 32 had lump in the right breast and 23 had lump in the left breast.In both right and left breasts, highest percentage was located in the upper and outer quadrant (29.09% and 18.18% respectively).

) (Table-I)
Cytologic findings (FNAC): Out of 55 cases, 54 were ductal carcinoma and only one was mucinous carcinoma.Out of the 54 ductal carcinoma (NOS), 11 were in grade-I, 43 were in grade-II.No case was diagnosed as grade-III (Fig- 3).

Histologic findings:
Out of 55 patients, 54 were diagnosed as invasive ductal carcinoma (NOS) and one was mucinous carcinoma.Among 54 patients with invasive ductal carcinoma (NOS), 36 cases were in grade-II, 17 were in grade-I and one was in grade-III.(Fig- 4).
Cytologic grading compared with the histologic grade: It was found that out of 17 cases of histological grade-I, 10 were cytologically in grade-I and 7 were in grade-II.Out of 36 cases which were histologically in grade-II, 35 were cytologically in grade-II and one was in grade-I.One patient with histological grade-III was grade-II cytologically (Fig- 5).
Statistical analysis by Chi-square test showed that cytological grade significantly correlated with histological grade, P<0.001.

Evaluation of cytopathologic diagnosis and histologic findings:
In this study, the sensitivity of the test (FNAC) to diagnose malignant breast diseases was 100%.
The overall diagnostic accuracy of FNAC in the present study was 100%.Statistical analysis by Chi-square test revealed Chi-square value 10.83 (P< 0.001), which is statistically significant.Sensitivity of FNAC obtained by various workers ranges from 97% to100% and present study correlates with that study (Table-II).So there is strong correlation between cytologically malignant cases with their histologic findings.

Conclusion:
The present study shows that FNAC is a reliable method.It helps to confirm the clinical impression without open biopsy.The most important aspect of this procedure lies on the diagnosis of malignancy.With adequate number of trained cytopathologists this procedure can be extended to all the Medical Colleges and district hospitals of Bangladesh and this will help in pre-operative management of the patients and to take decision about the type of surgery.From this study it can be concluded that diagnosis of breast carcinoma from fine needle aspiration cytology (FNAC) should be practiced as a routine procedure as there is a high degree of correlation with histopathological findings.Now-a-days, neoadjuvant chemotherapy is increasingly being offered to the patients with invasive breast carcinoma.In this regard, FNAC as an alternative to histological examination is an important denominator for planning of management where core biopsy of breast is not practised in Bangladesh.Experience gained from this study further advocates that FNAC could be an ideal method for follow-up of malignant cases, especially when there is recurrence.

Table - II
Comparative evaluation of FNAC of the present study with other studies.Breast cancer is one of the common clinical problems in Bangladesh.Although there has been little success in preventing breast cancer, significant reduction of mortality could be achieved by early detection.It is the general consensus that a firm pre-operative diagnosis should be established before surgery and FNAC is an extremely useful diagnostic technique.It has already been established that FNAC is an easily performed outpatient diagnostic method for determining the nature of breast lesion.Its success is due to its diagnostic accuracy and its cost effectiveness in the management of breast lump.