Diagnosis of Follicular Variant of Papillary Thyroid Cancer: Is Frozen Section a Guide for the Surgeon?

Hakan Kaya, Burak Ertaş, Neslihan Kurtulmuş, Ümit İnce, Serdar Giray and Mete Düren

Thyroid Clinic of Acıbadem Medical Faculty Hospital, Acıbadem University, Turkey
Department of Otorhinolaryngology, Acıbadem University, Turkey
Department of Endocrinology, Division of Internal Medicine, Acıbadem University, Turkey
Department of Pathology, Acıbadem University, Turkey

^*Correspondance to: Hakan Kaya 

 PDF  Full Text DOI: 10.25107/2474-1647.1210

Abstract

Introduction: Fine needle aspiration cytology (FNAC) is a useful tool in the diagnosis of papillary thyroid cancer (PTC). However, it is difficult to diagnose the follicular variant of PTC (FVPTC) preoperatively via FNAC or frozen section (FS) examination. In this retrospective study, we measured the sensitivities of, and extent of agreement between, these two diagnostic tools in patients ultimately diagnosed with FVPTC.Materials and
Methods: Between November 2013 and December 2014, a total of 100 patients were diagnosed with FVPTC and operated upon in the Thyroid Clinic of Acibadem Hospital. All patients were operated upon by the same surgeon, and all FNAC and FS data were evaluated by the same cytopathologist and histopathologist, respectively. The sensitivities of FNAC and FS were determined, and the Kappa test was used to calculate the extent of agreement between the two tools.Results: A total of 78 patients underwent bilateral total thyroidectomy and 22 completion thyroidectomy following diagnostic lobectomy. The FNAC results were benign (25%), atypical cells/ follicular lesions of unknown significance (AFCUS) (14%), follicular neoplasia (31%), suspicious for PTC (18%), and PTC (12%). The FS results were benign (27%), follicular neoplasia (46%), suspicious for PTC (13%), and PTC (14%). Surgery was scheduled for patients with nodules larger than 3 cm that were benign on FNAC, those who had nodules of any size and were repeatedly of FNAC AFCUS status, and those who had nodules of any size and FNAC indications of follicular neoplasia, suspicion of PTC, or PTC. The sensitivity of FNAC used to diagnose FVPTC was 32.4% and that of FS 34.1%. Moderate agreement was evident between the two diagnostic tools, with a Kappa value of 0.423 (95% confidence interval, 0.078-0.747). Patients for whom the FS data raised a suspicion of PTC or indicated the presence of PTC underwent bilateral total thyroidectomy as the initial surgery. The initial surgical strategy was changed in 17% of patients after FS analysis indicated a suspicion of PTC or PTC.Conclusion: Although the utility of FS data is debatable in patients who undergo surgery for treatment of thyroid nodules, we found that the FS results may change the initial surgical strategy and reduce the need for completion thyroidectomy.

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Cite the article

Kaya H, Ertas B, Kurtulmus N, Ince U, Giray S, Duren M. Diagnosis of Follicular Variant of Papillary Thyroid Cancer: Is Frozen Section a Guide for the Surgeon? Clin Surg. 2016; 1: 1210.