Abstract
Objective : The present study was performed to clarify the cytological characteristics useful in the differential diagnosis between low grade ductal carcinoma which is mainly composed of small nuclei and benign breast lesions.
Study Design : Fine needle aspiration cytology specimens of 37 cases of breast cancer and 13 benign breast lesions were examined in the following categories : 1) appearance of bare bipolar nuclei ; 2) overlapping pattern of cells ; 3) presence of isolated cells ; 4) appearance of prominent nucleoli ; 5) pattern of chromatin distribution ; and 6) presence of nuclear groove. All the 50 cases were initially diagnosed as suspected malignancy or were difficult to diagnose, because the 37 cases of breast cancer had small nuclei with mild atypia, and the 13 benign breast lesions demonstrated the obscure presence of myoepithelial cells in the cell clusters.
Results : Univariate analysis revealed that the number of bare bipolar nuclei (p=0.007), and presence of nuclear grooves (p=0.02) were statistically significant factors. When cases scored more than 4 points from the two factors suggesting malignancy as follows (many bare bipolar nuclei, score 1 ; a few bare bipolar nuclei, score 2 ; and lack of bare bipolar nuclei, score 3 ; lack of nuclear grooves, score 1 ; and presence of nuclear grooves, score 2), they were categorized as breast cancer. The categorization showed a sensitivity of 76%, specificity of 77%, positive predictive value of 90% and negative predictive value of 53%.
Conclusion : Examination of bipolar bare nuclei and nuclear margins might be useful in the differential diagnosis between benign and malignant breast lesions.
