EWSR1 rearrangement in papillary thyroid microcarcinoma is related to classic morphology and the presence of small-cell phenotype

Authors

  • Bozidar Kovacevic Institute of Pathology and Forensic Medicine, Military Medical Academy https://orcid.org/0000-0002-3270-0170
  • Ana Caramelo Ipatimup Diagnostics, Institute of Molecular Pathology and Immunology of Porto University, Ipatimup, Porto, Portugal https://orcid.org/0000-0002-5625-9703
  • Vesna Skuletic Institute of Pathology and Forensic Medicine, Military Medical Academy, Belgrade, Serbia https://orcid.org/0000-0002-1942-7149
  • Snezana Cerovic Institute of Pathology and Forensic Medicine, Military Medical Academy, Belgrade, Serbia https://orcid.org/0000-0002-1649-2092
  • Catarina Eloy Ipatimup Diagnostics, Institute of Molecular Pathology and Immunology of Porto University, Ipatimup, Porto, Portugal; Medical Faculty, University of Porto, Porto, Portugal

DOI:

https://doi.org/10.17305/bjbms.2021.6181

Keywords:

Papillary thyroid carcinoma, small cells, EWSR1, EWSR-FLI1, carcinoma of the thyroid, Ewing family tumor elements

Abstract

The EWSR1 rearrangements with unknown genes were detected in a high percentage of classic variants of papillary thyroid carcinoma. The small-cell carcinoma of the thyroid with Ewing family tumor elements (CEFTE) typically presents with EWSR1-FLI1 rearrangement suggesting the possible role of EWSR-FLI1 translocation in the loss of thyroid differentiation and acquisition of a small-cell phenotype. In order to determine the frequency and association of EWSR1 rearrangements, particularly the EWSR1-FLI1 fusion with clinicopathological features of papillary thyroid microcarcinoma (m-PTC) and the presence of small cells, we analyzed a series of 99 m-PTCs using the fluorescence in situ hybridization method.  Ninety cases (90.9%) of m-PTC were positive for small cells. This group of m-PTC has shown more often invasive growth, lymphatics invasion, and moderate/extended intratumoral fibrosis. Three cases out of 99 were inconclusive for EWSR1 rearrangement. Eighty-nine (92.7%) and twenty-seven (28.1%) out of 96 m-PTC cases were positive for EWSR1 rearrangement and EWSR1-FLI1 fusion, respectively. m-PTC with classical architectural pattern presented more frequently with EWSR1 rearrangement relative to m-PTC with other patterns (p = 0.005). Other clinicopathological features were not related to the presence of EWSR1 rearrangement or EWSR1-FLI1 fusion. The percentage of small cells present significantly correlated with the percentage of cells positive for EWSR1-FLI1 fusion (p = 0.05) and EWSR1 rearrangement (p <0.001). EWSR1-FLI1 fusion is not rare in m-PTC and it is associated with the acquisition of small-cell phenotype. The EWSR1 gene rearrangement is a frequent event in m-PTC and is related to the classical pattern of m-PTC.

Downloads

Download data is not yet available.
EWSR1 rearrangement in papillary thyroid microcarcinoma is related to classic morphology and the presence of small-cell phenotype

Downloads

Additional Files

Published

01-02-2022

Issue

Section

Pathology

Categories

How to Cite

1.
EWSR1 rearrangement in papillary thyroid microcarcinoma is related to classic morphology and the presence of small-cell phenotype. Biomol Biomed [Internet]. 2022 Feb. 1 [cited 2024 Jun. 22];22(1):54-63. Available from: https://www.bjbms.org/ojs/index.php/bjbms/article/view/6181