Papillary thyroid carcinoma, a diagnostic approach in fine needle aspiration: Review of literature

Background: Despite well-defined cytology features of papillary thyroid carcinoma (PTC) in fine needle aspiration (FNA), diagnostic difficulties do exist while making decision in respect to papillary thyroid carcinoma (PTC) cases. Aims: The aim of this study is to clarify diagnostic significance of various cytology features of PTC and to identify possible diagnostic pitfalls. Materials and Methods: FNA cytology (FNAC) features and clinical findings of 17 PTC cases diagnosed on histology were retrieved. A retrospective review of these cases was performed. Results: The frequency and number of papillary formations, intranuclear cytoplasmic inclusions (INCI), and nuclear grooves (NG) was more in PTC cases as compared to suggestive/suspicious of (S/O) and rule out (R/O) PTC cases. Cyst macrophages forming clusters were seen in six cases. Multinucleated giant cells (MGC) were seen in seven cases. Large MGC with dense cytoplasm and more nuclei were seen in four PTC and one S/O PTC cases. Conclusion: FNAC features of PTC in FNA smears are neither constant nor specific. All the cytology features of PTC should be reported in proper context which allows endocrine specialist to treat and urgent histological verification.