Journal of pathology and translational medicine 2018 01 29() doi 10.4132/jptm.2018.01.17
It is difficult to correctly diagnose follicular neoplasms (FNs) using FNAC because it shares many cytological features with other mimicking lesions. The aim of this study was to identify the cytological features that differentiate FNs from mimicking lesions.
Materials and Methods
We included the cytological slides from 116 cases of thyroid FN diagnosed using FNAC, and included their subsequent histological diagnoses. We evaluated the cytological architectural pattern and nuclear features of the lesions according to their histological groups.
The final histological diagnoses of the 116 cases varied, and included fifty-one follicular neoplasms (44%), forty-seven papillary thyroid carcinomas (40%) including follicular variant, and seventeen cellular nodular hyperplasias (NH; 15%). Regardless of the final histological diagnosis, microfollicular pattern was observed in most cases. On the other hand, trabecular pattern was identified in 34% of FNs, but was not observed in any other lesions. Additionally, elongated nuclei and ground glass chromatin were only found in some of papillary thyroid carcinomas.
This study shows that the trabecular pattern is a representative cytological feature of FNs that can be used to distinguish FNs from mimicking lesions. In addition, nuclear shape and chromatin pattern can be used to further confirm the diagnosis of FNs from mimicking lesions through FNAC.