title: Paraganglioma of the thyroid gland: a rare entity.
abstract: Paragangliomas are neuroendocrine tumors. The thyroid gland is one of the anatomic sites in which paraganglia are not normally located and are exceptionally rare. We report a case of a 36-year-old Hispanic woman with a soft mass measuring about 30 mm in the right thyroid lobe. Patient was operated on and the neoplasm showed microscopically a typical nesting organoid pattern (zellballen). The inmunohistochemical analysis revealed that the tumor showed strongly and diffuse stain for NSE, Synaptophysin, Chromogranin A, and S-100 protein in the sustentacular cells, whereas no inmunoreactivity was detected with antibodies against thyroglobulin, calcitonin, TTF-1, CEA, and AE1-AE3. The MIB-1 labeling showed 7% of neoplastic cells. Head and neck paragangliomas usually develop slowly, and this tumor exhibited a low proliferative activity. In view of the uncertain malignant potential of paragangliomas, we recommended a careful long-term follow-up.
authors.affiliation: Department of Otolaryngology, Complexo Hospitalario Universitario A Coruña, A Coruña, Spain, nicolas.gonzalez@canalejo.org.
authors.forename: Nicolás
authors.initials: N
authors.lastname: González Poggioli
authors.forename: Manuel
authors.initials: M
authors.lastname: López Amado
authors.forename: María Teresa Yebra
authors.initials: MT
authors.lastname: Pimentel
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D010236:Paraganglioma, Extra-Adrenal / Q000378:metabolism / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor