<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Background: Papillary thyroid microcarcinoma (PTMC) defines a group of papillary thyroid carcinomas, incidentally discovered, measuring 1 cm or less. The aim of our study was to evaluate the incidence and the pathological characteristics of PTMCs in our institution in the last 25 years, with special emphasis on the prognostic factors related to PTMCs. Material and methods: We performed a retrospective, cohort study on 255 PTMCs, registered in the Department of Pathology, Tîrgu-Mureş Emergency County Hospital between 1990 and 2014. Results: A significant increase in the incidence of PTMCs was observed in the 2004-2014 period, compared to 1990-2003 (7.6%, 229 PTMCs/3005 thyroid specimens vs. 1.2%, 23 PTMCs/1885 thyroid specimens). Conventional PTMCs accounted for most of PTMC cases (n=123 cases, 48.2%), followed by the follicular variant of PTC (n=117 cases, 45.9%). The increasing incidence of PTMCs was associated with a significant increase in the routine number of blocks sampled per case over the study period (R2 =0.72, p &lt; 0.001). By means of the univariate and multivariate analysis, three risk factors were predictive for extrathyroidal extension in PTMCs: multifocality (Odds ratio [OR] 4.97, p-0.002), tumor size ≥ 5mm (OR 8.97, p-0.008) and lymph node involvement (OR 17.66 p&lt;0.005). Conclusion: The incidence of PTMCs has revealed a significant increasing trend in our institution over the last 25 years. Multifocality, lymph node involvement and tumor size ≥ 5mm were found to be risk factors for extrathyroidal extension. These prognostic factors must be evaluated and clearly mentioned in the pathological report, to help a correct estimation of biological potential of the lesion and an appropriate postoperative management.</p></abstract>

Background: Papillary thyroid microcarcinoma (PTMC) defines a group of papillary thyroid carcinomas, incidentally discovered, measuring 1 cm or less. The aim of our study was to evaluate the incidence and the pathological characteristics of PTMCs in our institution in the last 25 years, with special emphasis on the prognostic factors related to PTMCs. Material and methods: We performed a retrospective, cohort study on 255 PTMCs, registered in the Department of Pathology, Tîrgu-Mureş Emergency County Hospital between 1990 and 2014. Results: A significant increase in the incidence of PTMCs was observed in the 2004-2014 period, compared to 1990-2003 (7.6%, 229 PTMCs/3005 thyroid specimens vs. 1.2%, 23 PTMCs/1885 thyroid specimens). Conventional PTMCs accounted for most of PTMC cases (n=123 cases, 48.2%), followed by the follicular variant of PTC (n=117 cases, 45.9%). The increasing incidence of PTMCs was associated with a significant increase in the routine number of blocks sampled per case over the study period (R2 =0.72, p < 0.001). By means of the univariate and multivariate analysis, three risk factors were predictive for extrathyroidal extension in PTMCs: multifocality (Odds ratio [OR] 4.97, p-0.002), tumor size ≥ 5mm (OR 8.97, p-0.008) and lymph node involvement (OR 17.66 p<0.005). Conclusion: The incidence of PTMCs has revealed a significant increasing trend in our institution over the last 25 years. Multifocality, lymph node involvement and tumor size ≥ 5mm were found to be risk factors for extrathyroidal extension. These prognostic factors must be evaluated and clearly mentioned in the pathological report, to help a correct estimation of biological potential of the lesion and an appropriate postoperative management.

Papillary Thyroid Microcarcinomas: a 25 Years Retrospective, Institutional Study of 255 Cases

Departament of Endocrinology, Emergency County Hospital, Tirgu Mures, Romania

Departament of Endocrinology, University of Medicine and Pharmacy of Tirgu Mures, Romania

Departament of Histology, University of Medicine and Pharmacy of Tirgu Mures, Romania

Departament of Epidemiology, University of Medicine and Pharmacy of Tirgu Mures, Romania

Departament of Pathology, Emergency County Hospital, Tirgu Mures, Romania

Acta Marisiensis - Seria Medica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Background: Papillary thyroid microcarcinoma (PTMC) defines a group of papillary thyroid carcinomas, incidentally discovered, measuring 1 cm or less. The aim...

Papillary Thyroid Microcarcinomas: a 25 Years Retrospective, Institutional Study of 255 Cases

Published Online: Feb 09, 2016

Page range: 41 - 46

Received: Aug 13, 2015

Accepted: Sep 03, 2015

DOI: https://doi.org/10.1515/amma-2015-0108

Keywords
microcarcinoma, incidence, number of blocks, extrathyroidal extension, multifocality

© by Adela Nechifor Boilă

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Papillary Thyroid Microcarcinomas: a 25 Years Retrospective, Institutional Study of 255 Cases

Published Online: Feb 09, 2016

Page range: 41 - 46

Received: Aug 13, 2015

Accepted: Sep 03, 2015

DOI: https://doi.org/10.1515/amma-2015-0108

Keywordsmicrocarcinoma, incidence, number of blocks, extrathyroidal extension, multifocality

© by Adela Nechifor Boilă

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
microcarcinoma, incidence, number of blocks, extrathyroidal extension, multifocality