Abstract
Objective : Reports on liquid based cytology (LBC) of the thyroid are rare. The aim of this report was to clarify the cytological findings in thyroid disorders and discuss the significance of LBC of the thyroid.
Study Design : We examined 437 thyroid nodules by fine-needle aspiration cytology in Kuma Hospital from February to May 2012. After smears of the aspirated materials were prepared by the conventional method, we washed out the needles with LBC fixatives to obtain samples for the SurePath method.
Results : Preparations obtained using the CytoRichTM RED (CR-R) fixative showed a clean background and shrinkage of the cells in comparison with those obtained using the CytoRichTM BLUE (CR-B) fixative ; there were hardly any lymphocytes in the latter preparations. In comparison with the case in the conventional preparations (C-P), the N/C ratio and malignant/benign cell ratio in the LBC preparations (LBC-P) tended to be higher. The ground glass nuclei of papillary carcinoma could not be distinguished in the LBC-P. Clear zones surrounding the cell clusters was observed in adenomatous goiter, and zigzag nuclear membranes (convoluted nuclei) were observed in papillary carcinoma. The insufficient material rates were 8.1% for C-P, 5.3% for LBC-P, and 2.2% in cases where both methods were used.
Conclusion : Additional processing for LBC using materials adherent to the needles after preparation of the conventional smears can reduce the insufficiency rates in thyroid aspiration cytology. It is important to be aware of the cytological differences between C-P and LBC-P.
