Influence of imaging on touch imprint cytology of breast lesions

Touch imprint cytology (TIC) facilitates rapid diagnosis of breast diseases in women attending triple assessment clinics. Some pathologists, in our centre, feel that pathological interpretation of TIC slides is contentious when the lesions are radiologically indeterminate (R3), as these can lead to potentially higher false positive or false negative cytology results. We hypothesised that: '(R3) lesions are more likely to have higher false positive or false negative TIC and/or be inadequate for TIC assessment'. In other words, 'imaging influences cytological classification especially when indeterminate'.

Review of the data collected in our centre between December 2003 and July 2005. All patients who attended the one stop symptomatic breast clinic and had a TIC performed following an ultrasound (US) guided core biopsy (CB) were included. Demographic, radiological, cytological and core biopsy grading data were collected. Cytology grading was correlated with radiology classification to assess our hypothesis.

A total of 248 patients underwent 254 CB/TIC. The average patient's age of the group was 54 years (range of 29-95). On TIC, 186 (73%) were deemed malignant, 23(9%) benign while 33(13%) were inadequate for assessment. There was no false positive or false negative TIC. There was good correlation between TIC and CB results (p<0.0001). Thirty-three cases were inadequate (C1) for cytology assessment, of these 16 (48.5%) were indeterminate on imaging. R3 lesions were 6 times more prone to have C1 cytology (p<0.0001).

Touch imprint cytology is a reliable and efficient method in running a one stop breast clinic, with the backup of full tissue diagnosis. Careful selection of cases that would benefit from this technique is highly recommended as a significant number of radiologically indeterminate lesions are likely to be insufficient for cytological assessment. Further prospective trials are required to assess this further. Until then the diagnosis in this sub-group should depend on core biopsy.