A Comparison of Clinicopathological Characteristics and Short-Term Outcome of Papillary Thyroid Carcinoma with Tall Cell Histology and Classic Papillary Thyroid Carcinoma: A Single-Institution Experience.

Context: Papillary thyroid carcinoma with tall cell histology (PTC-TCH) is an aggressive subtype in terms of clinicopathological features and outcome. Even 10% of tall cells can show aggressive features. Aims: The aim of this study is to investigate the behavior of PTC-TCH, to compare with classic PTC (cPTC), and evaluate the short-term outcome. Settings and Design: This is a retrospective analysis of patients with cPTC and those with TCH (PTC-TCH) seen from January 2010 to May 2017 seen in our Thyroid Cancer Clinic. Materials and Methods: A total of 40 patients with TCH were compared with 352 cPTC and evaluated for age, gender, tumor size, presence of multifocality, capsular, vascular invasion, extrathyroid extension, and appearance of metastases. Short-term response to therapy was assessed using the 2015 American Thyroid Association guidelines. Statistical Analysis: P < 0.05 was considered statistically significant. All analyses were performed with SPSS software (Version 21.0, Chicago, IL, USA). Results: PTC with TCH presented at a younger age, had larger tumors, and more extrathyroid extension. Seven out of 40 cases developed lung metastases, (17.5% vs. 4.5% in cPTC), within a year of diagnosis. Conclusion: PTC-TCH irrespective of percentage of tall cells showed aggressive features and early metastases. They should be recognized early as an aggressive subtype and treated intensively. Close follow-up must be instituted to look for metastases, especially to the lungs. [ABSTRACT FROM AUTHOR]