Abstract
Objective : We investigated the usefulness of some cytological features for the diagnosis of poorly differentiated thyroid carcinoma.
Method : The cytological findings of a total of 19 cases that had been histologically diagnosed as poorly differentiated thyroid carcinoma were compared with those of papillary carcinoma (20 cases) and follicular tumors (14 cases), focusing on such characteristics as the cell number, lack of colloid, solid/trabecular/insular (STI) component, N/C ratio, nuclear atypia, anisokaryosis, necrosis, severe crowded clusters, and endothelial wrapping image.
Results : Poorly differentiated thyroid carcinoma showed the following features at significantly higher frequencies as compared to papillary carcinoma : STI component (p<0.01), anisokaryosis (p<0.01), nuclear atypia (p<0.01), lack of colloid (p=0.02), and mitoses (p=0.02), and the following features at significantly higher frequencies as compared to follicular carcinoma : STI component (p<0.01), anisokaryosis (p<0.01), and mitoses (p<0.05). Cases were divided into 2 groups, a group showing overlap of≧5 items, and another showing overlap of≤4 items. Statistically significant difference between the two groups was observed in respect of overlapping of the STI component and anisokaryosis (p<0.01), and also overlapping of the STI component and nuclear atypia (p=0.0001).
Conclusion : Matching of more than 5 features including the STI component, which is the essential feature, is required to achieve a confirmatory diagnosis of poorly differentiated thyroid carcinoma.
