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International Journal of Endocrinology
Volume 2018 (2018), Article ID 4682876, 10 pages
https://doi.org/10.1155/2018/4682876
Research Article

Histopathological Characterization and Whole Exome Sequencing of Ectopic Thyroid: Fetal Architecture in a Functional Ectopic Gland from Adult Patient

1Thyroid Unit, Cellular and Molecular Endocrine Laboratory, LIM-25, Faculdade de Medicina da Universidade de São Paulo (FMUSP), Avenida Doutor Arnaldo 455, Cerqueira César, 01246-904 São Paulo, SP, Brazil
2Adolfo Lutz Institute, São Paulo Public Health Service, Av. Dr. Arnaldo 355, Cerqueira César, 01246-000 São Paulo, SP, Brazil
3Head and Neck Surgery of Santa Catarina Hospital, Av. Paulista 200, Bela Vista, 01310-000 São Paulo, SP, Brazil
4Department of Internal Medicine, Botucatu School of Medicine, UNESP, Av. Prof. Montenegro, s/n Distrito de Rubião Junior, 18618-687 Botucatu, SP, Brazil
5Servicio de Endocrinología, Hospital de Pediatría Dr. Juan Garrahan, Combate de los Pozos 1881, C1245AAM Buenos Aires, Argentina
6Departamento de Cirurgia na Disciplina de Cirurgia de Cabeça e Pescoço da Faculdade de Ciências Médicas da UNICAMP, R. Tessália Vieira de Camargo 126, 13083-887 Campinas, SP, Brazil
7Medicine School, Universidade de Fortaleza (Unifor), Av. Washington Soares 1321, Edson Queiroz, 60811-905 Fortaleza, CE, Brazil
8Postgraduate Program in Biotechnology, Universidade Federal de São Paulo (UNIFESP), Pedro de Toledo 669, 040399-032 São Paulo, SP, Brazil
9Thyroid Molecular Sciences Laboratory, Universidade Federal de São Paulo, Departamento de Ciências Biológicas, Postgraduation Programs in Biotechnology and Structural and Functional Biology, UNIFESP, Pedro de Toledo 669, 040399-032 São Paulo, SP, Brazil
10Molecular Oncology Center, Hospital Sírio-Libanés, Rua Prof. Daher Cutait 69, 01308-060 São Paulo, SP, Brazil

Correspondence should be addressed to Ileana Gabriela Sanchez Rubio; rb.psefinu@oibur.anaeli

Received 30 August 2017; Accepted 16 November 2017; Published 8 February 2018

Academic Editor: Maria L. Dufau

Copyright © 2018 Rosalinda Yasato Camargo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ectopic thyroid results from a migration defect of the developing gland during embryogenesis causing congenital hypothyroidism. But it has also been detected in asymptomatic individuals. This study aimed to investigate the histopathological, functional, and genetic features of human ectopic thyroids. Six samples were histologically examined, and the expression of the specific thyroid proteins was assessed by immunohistochemistry. Two samples were submitted to whole exome sequencing. An oropharynx sample showed immature fetal architecture tissue with clusters or cords of oval thyrocytes and small follicles; one sample exhibited a normal thyroid pattern while four showed colloid goiter. All ectopic thyroids expressed the specific thyroid genes and T4 at similar locations to those observed in normal thyroid. No somatic mutations associated with ectopic thyroid were found. This is the first immature thyroid fetal tissue observed in an ectopic thyroid due to the arrest of structural differentiation early in the colloid stage of development that proved able to synthesize thyroid hormone but not to respond to TSH. Despite the ability of all ectopic thyroids to synthetize specific thyroid proteins and T4, at some point in life, it may be insufficient to support body growth leading to hypothyroidism, as observed in some of the patients.