Diagnostic Accuracy of Intraoperative Touch Imprint Cytology for the Diagnosis of Axillary Sentinel Lymph Node Metastasis of Breast Cancer: Comparison With Intraoperative Frozen Section Evaluation.

Atif A Hashmi,Syed Rafay Yaqeen,Muhammad Irfan,Anoshia Afzal,Ishaq Azeem Asghar,Naveen Faridi,Omer Ahmed,Samreen Naz

doi:10.7759/cureus.12960

Abstract

IntroductionThe intraoperative frozen section is a recommended method to detect breast cancer metastasis to axillary sentinel lymph nodes (SLNs); however, frozen section is not widely available and requires an experienced staff. Alternatively, touch imprint cytology (TIC) is a simple and cost-effective technique to detect metastasis. Therefore, in this study, we assessed the diagnostic accuracy of TIC for detecting SLN metastasis and compared it with intraoperative frozen section evaluation.MethodologyA retrospective study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, for a duration of two years. A total of 114 patients undergoing surgery for primary breast cancer were included in the study. All patients had clinically and radiologically negative axillary lymph nodes. SLN sampling was done using radioactive dye and sent for intraoperative consultation. The SLNs were sliced at 4-mm intervals and two TIC slides and three step-levels for frozen section were prepared, and the results were compared with final (paraffin) section histology.ResultsThe sensitivity, specificity, and diagnostic accuracy of TIC was 83.7%, 98.5%, and 92.1%, respectively. Alternatively, the sensitivity, specificity, and diagnostic accuracy of frozen section was 93.9%, 100%, and 97.4%, respectively. The sensitivity of TIC and frozen section for detecting micrometastasis was 14.3% and 57.1%, respectively, with a diagnostic accuracy of 90.3% and 95.8%, respectively. Alternatively, with respect to macrometastasis, the sensitivity and specificity of TIC were 95.2% and 98.5%, respectively, while the sensitivity and specificity of frozen section were 100%.ConclusionTIC is a quick and effective technique for detecting breast cancer metastasis in axillary SLNs. Although frozen section had an overall higher sensitivity than TIC, the sensitivity of TIC for detecting macrometastasis was comparable to the frozen section. Therefore, we conclude that TIC is a good alternative to the frozen section in facilities where the frozen section is not available.

Highlights

The intraoperative frozen section is a recommended method to detect breast cancer metastasis to axillary sentinel lymph nodes (SLNs); frozen section is not widely available and requires an experienced staff
The sensitivity of touch imprint cytology (TIC) and frozen section for detecting micrometastasis was 14.3% and 57.1%, respectively, with a diagnostic accuracy of 90.3% and 95.8%, respectively
Sensitivity of frozen section was better than TIC for detecting breast cancer metastasis to axillary SLNs, TIC has several advantages over frozen section, such as low cost and rapid turnover time

Summary

Methods

A total of 114 patients undergoing surgery for primary breast cancer were included in the study. Patients with evidence of systemic metastases along with those who received post-neoadjuvant chemoradiation before surgery were excluded from the study. All patients had clinically and radiologically negative axillary LNs. SLN sampling was done using radioactive dye and sent for intraoperative consultation. The number of SLNs was recorded along with size. SLNs measuring smaller than 4 mm were bivalved along the hilum. SLNs measuring larger than 4 mm were bread-loafed at 2 mm interval. Two TIC slides were prepared from each cut surface of all SLNs and stained with DiffQuik and hematoxylin and eosin (H&E) stains. All slices of SLNs were submitted entirely for frozen section analysis. Three step-levels were prepared from each block and stained with H&E and examined by experienced histopathologists (Figure 1)

Results

Discussion

Conclusion