Papillary thyroid carcinoma: how much should the surgeon read from fine needle aspiration cytology reports?

During routine fine needle aspiration cytodiagnosis of papillary thyroid carcinoma (PTC), a number of cases are diagnosed as suspicious; or it is suggested that PTC or a neoplasm be ruled out by histopathology. Since these diagnostic labels are likely to put the clinicians in a difficult situation while planning the management, this study aims to find out how much the surgeon should read from these reports.

The patients were divided into two groups. Group A included 38 cases diagnosed as PTC or suspicious of PTC. Group B included 40 cases in which it was suggested that PTC/a neoplasm to be ruled out and non-neoplastic lesions with one or more cytologic features of PTC. The two groups were compared with clinical, imaging and cytomorphologic features.

A significant difference was observed with respect to age between Group A and Group B (P<0.001). The frequency of the following five cytologic features was significantly higher in Group A: papillary formation (P<0.001), psammoma bodies (P=0.054), fine nuclear chromatin (P=0.010), frequent nuclear grooves (P<0.001) and intra-nuclear cytoplasmic inclusion (P<0.001). Three or more of the five cytologic features were also reported in significantly higher number of Group A cases (P<0.001). Majority (81.8%) of the cases with subsequent histology in Group A were confirmed as PTC as opposed to 7.7% in Group B (P<0.001).

Thus, cases with definitive cytodiagnosis of PTC and suggestive of PTC (Group A) should be taken much more seriously by the surgeons as compared to Group B cases.