[Quality control in aspiration biopsy cytology]

Comparison and quality control of our experience of thyroid cytology (784 samples) and breast cytology (1,202 samples) were reported. False positive rate and other parameters were superior in breast cytology than thyroid. It may be due to the fact that cytological diagnostic criteria for follicular thyroid carcinoma from follicular adenoma is not established yet. More suspicious diagnosis in thyroid than breast also give low incidence of malignancy in thyroid suspicious diagnosis. As recommended by a guideline for both thyroid and breast cytology from the Papanicolaou society et al, conservative handling and protective diagnosis may help to reduce false positive and false negative rates.