title: Calcitonin-Negative Neuroendocrine Tumor of the Thyroid.
abstract: Neuroendocrine tumors (NETs) of the thyroid are rare; the most common type is medullary thyroid carcinoma (MTC). They are derived from parafollicular cells (C-cells) that usually express calcitonin, chromogranin, and carcinoembryonic antigen. Calcitonin-negative NETs of the thyroid are extremely rare, and the origin of these tumors is unclear. Whereas some believe that these tumors are from follicular cells, recent reports have shown expression of calcitonin gene-related peptide in these tumors, indicating parafollicular C-cell origin. Here, we report a case of calcitonin-negative NET of the thyroid in a 74-year-old woman, with review of the literature.
authors.affiliation: 1 Texas Tech University Health Sciences Center, El Paso, TX, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Parmer
authors.affiliation: 1 Texas Tech University Health Sciences Center, El Paso, TX, USA.
authors.forename: Stacey
authors.initials: S
authors.lastname: Milan
authors.affiliation: 1 Texas Tech University Health Sciences Center, El Paso, TX, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Torabi
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002116:Calcitonin / Q000032:analysis / Q000096:biosynthesis; D005260:Female; D006801:Humans; D018358:Neuroendocrine Tumors / Q000175:diagnosis*; D013964:Thyroid Neoplasms / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; D002116:Calcitonin
keywords: calcitonin; calcitonin gene–related peptide; neuroendocrine; thyroid