Background: Sentinel lymph node biopsy is a procedure that examines the first tumour-draining lymph node. Touch imprint cytology may provide a quick method for intraoperative screening of sentinel lymph nodes for the presence of metastases.
Methods: Touch imprint cytological analysis of sentinel lymph nodes was compared prospectively with the findings obtained on routine paraffin sections. Touch imprint slides from 55 patients with breast cancer were prepared during operation from multiple sections of sentinel lymph nodes, stained with haematoxylin and eosin. A cytopathologist blinded to the histological results interpreted the smears.
Results: The concordance between touch imprint and paraffin sections of sentinel lymph nodes was 98 per cent (54 of 55). When touch imprint analysis of sentinel lymph nodes was compared with paraffin sectioning of all lymph nodes from the axillary node dissection, the concordance was 95 per cent (52 of 55). The sensitivity and specificity of sentinel lymph node touch imprints in detecting metastases were 82 and 100 per cent respectively. The positive and negative predictive values were 100 and 93 per cent respectively.
Conclusion: Touch imprint cytology is potentially useful for the intraoperative evaluation of sentinel lymph nodes in patients with breast cancer.