Cytological characteristics of papillary thyroid carcinoma on LBC specimens, compared with conventional specimens

Background: The cytological findings in conventional specimens (C-S) and liquid-based cytology specimens (LBC-S) are not quite same. The aim of this article is to clarify the cytological findings of papillary thyroid carcinoma (PTC) characteristic of LBC-S.

Methods: Out of 5,971 cases diagnosed in a single institution from March to September in 2012, 161 PTC cases with both C-S and LBC-S were reviewed. Additionally, we compared the findings with those in LBC-S of 55 adenomatous or hyperplastic nodule (AN) and 21 follicular neoplasm (FN) cases.

Results: Compared to C-S, the incidences of trabecular and hobnail patterns, collagenous stroma, naked capillaries, intercellular spaces, convoluted nuclei, eosinophilic nucleoli, and perinucleolar halo were increased. Pale nuclei were observed in only one of 161 PTC cases. Specificity of convoluted nuclei and perinucleolar halo were 97.4% and 96.1%, respectively.

Conclusion: Convoluted nuclei and perinucleolar halo might become a new indicator of PTC in LBC-S. Contrarily, we should be aware that pale nuclei are rarely observed in LBC-S.