Fine Needle Aspiration Cytology for Diagnosis of Benign Breast Disease in A Resource-Limited Setting

Abstract

Background: A majority of breast lesion is benign in nature; benign breast disease is four times more common in Nigerian women. The percentage of unsatisfactory smears in breast cytology appears to be higher in benign conditions compared to malignant ones. The aim of this study is to determine the effectiveness of cytopathology in the diagnosis of benign breast disease in our institution.
Methodology: This is a prospective study of 96 patients with benign breast disease seen during the study period. The patients were subjected to clinical assessment, fine needle aspiration cytology (FNAC) and open biopsy histopathology (as standard reference test).
Results: One hundred and seventy-four patients with both FNAC and histopathology reports were initially evaluated, 96 (55.2%) had benign while the rest (78, 44.8%) harbored malignant lumps. On further analysis of the benign lumps, FNAC achieved high sensitivity (98.8%), specificity (96.9%) and overall diagnostic accuracy (98.0%) compared to clinical assessment with values of 83.3% (sensitivity), 82.1% (specificity) and 82.2% (overall diagnostic accuracy). The false positive rate (FPR, 2.3%) and false negative rate (FNR, 1.6%) reported for FNAC were equally better than figures of 14.9% (FPR) and 20.0% (FNR) documented for clinical assessment. Cytopathology was utilized in sub-classifying 76 (79.2%) out of the 96 biopsy confirmed benign lumps; 49 slides were correctly typed giving a concordant rate of 64.5%.
Conclusion: Fine needle aspiration cytology in our index study showed appreciable concordance with open biopsy histology in the diagnosis and sub-classification of benign breast disease.