Role of frozen section evaluation in patients with breast lumps: A study of 251 cases

Context: Frozen section is an invaluable intra-operative tool for evaluation of breast lumps. Aims: The aim of this study was to (1) calculate the overall accuracy, false positivity, false negativity for frozen section of breast lumps, (2) analyze the causes of discrepancies, and (3) compare the data with that of published literature on frozen section of breast lumps. Material and Methods: Two hundred and fifty one frozen sections comprising 237 breast lumps, 10 axillary nodes and 4 lumpectomy margins received for frozen section in 1997 were analyzed. Pathology reports and slides (of both frozen and paraffin sections) were reviewed. The values were calculated using paraffin slides as the gold standard. Results: The 237 lumps received for primary diagnosis comprised 157 malignant and 80 benign lesions. The false negativity rate was 0.42%, false positive rate 0%, deferral rate 0.84%, overall accuracy rate was 99.57%. The false negative diagnosis was an error of interpretation. False negativity rate for axillary nodes was 20% and accuracy was 80%. Accuracy for margins was 100%. Conclusion: Frozen section has a role despite the raging popularity of aspiration cytology in the following settings: (1) Difficult cytology (2) Evaluation of lumpectomy margins. (3) Intra-operative nodal status