Intraoperative imprint cytology of sentinel lymph nodes in breast cancer: initial experience and lessons learnt in establishing a new practice.
OBJECTIVE
The initial 18 months experience of performing intraoperative imprint cytology for patients with breast cancer undergoing sentinel lymph node biopsy is described for a single institution. The learning process is compared with published results from institutions with many years of experience in order to assess progress in reaching those ideal results, and the methodology used by these institutions is reviewed.


METHODS
A retrospective review was undertaken of the intraoperative imprint cytology results from 103 patients with breast cancer (yielding a total of 170 lymph nodes) who underwent imprint cytology of their sentinel lymph node. The intraoperative imprint cytology results were compared with the final histopathological results. Details regarding the primary tumour characteristics and metastatic deposit size were recorded.


RESULTS
The sensitivity for imprint cytology was 31.1%, with a specificity of 100% and overall accuracy of 77.8%. The sensitivity for detecting macrometastases (>2 mm diameter) was 61.9% and the sensitivity for micrometastases (<2 mm diameter) and including isolated tumour cells was 4.2%.


CONCLUSIONS
The differences in sensitivity in comparison with many studies in the literature are multifactorial, and include technical aspects, such as the methodology used in the final histopathological and intraoperative evaluation of the sentinel lymph nodes, interpretative difficulties, and much lower case numbers. Furthermore, these numbers represent early experience and methods to improve sensitivity and overall accuracy are detailed in this paper.
Pathmanathan
Nirmala
N
Tissue Pathology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Sydney, New South Wales, Australia. pathmann@icpmr.wsahs.nsw.gov.au
Jones
Wayne
W
Salisbury
Elizabeth
E
Bilous
Michael
M
D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D003581:Cytodiagnosis / Q000379:methods; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*