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

Figure 1

Hematoxylin/eosin staining (a) (10x) and immunohistochemistry expression of specific thyroid genes in ectopic thyroid tissue sample 1 showing fetal architecture with clusters, cords and isolated epithelial oval cells, small follicles lined by cuboidal cells, and small areas of normal-sized follicles (b–h) (40x). TG: intense diffuse expression in the lumen of follicles and in cytoplasm of microfollicles and isolated thyrocytes (b). TPO: intense immunostaining in the apical membrane of micro- and normal-sized follicles; cytoplasmic TPO was observed in follicular cells and isolated thyrocytes (c). TSHR: scattered staining in the cytoplasm of thyrocytes (d). NKX2.1: strong diffuse nuclear immunostaining observed in most nuclei (e). PAX8: moderate or intense expression observed in around 80% of nuclei (f). NIS: diffuse cytoplasmic staining observed (g). Thyroxine (T4): diffuse and intense expression observed in the colloid of micro- and normal-sized follicles (h).

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