title: Parapharyngeal ectopic thyroid: the possible persistence of the lateral thyroid anlage. Clinical case report.
abstract: The accessory midline thyroids are ascribed to an arrest of migration of the median thyroid anlage, while the lateral ectopic thyroids have induced a hypothesis of the presence of lateral thyroid anlage. We report the case of a 67-year-old man who presented with dyspnea and dysphagia of 1 year's duration. The clinical examination and radiological investigations (CT and MRI) showed a solid heterogeneous mass in the right parapharyngeal space. The fine needle aspiration biopsy was inconsistent. The mass (3x2.5x3.5 cm) was excised via a transoral approach. It was capsulated with an elastic consistency and showed a nodular appearance on the cut surface. Histological examination revealed thyroid tissue with the characteristics of colloid goiter. The postoperative (99m)Tc-pertechnetate scan showed the normal thyroid gland located in the usual pretracheal site. The absence of malignancy, at histology and immunohistochemistry, allows a metastatic nature of the mass to be ruled out, and accounts for a supernumerary thyroid. The occurrence of a parapharyngeal thyroid, although extremely rare, is worth bearing in mind as a possible ectopic location. This case also supports the hypothesized role of the lateral thyroid anlage in man deriving from the ultimo-branchial body in the morphogenesis of the lateral lobe of the thyroid gland.
authors.affiliation: Department of Biomorphologies and Functional Sciences, Section of Anatomy and Histology, University of Napoli "Federico II", Via S. Pansini 5, 80131, Naples, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Soscia
authors.forename: G
authors.initials: G
authors.lastname: Guerra
authors.forename: M-P
authors.initials: MP
authors.lastname: Cinelli
authors.forename: D
authors.initials: D
authors.lastname: Testa
authors.forename: V
authors.initials: V
authors.lastname: Galli
authors.forename: V
authors.initials: V
authors.lastname: Macchi
authors.forename: R
authors.initials: R
authors.lastname: De Caro
mesh_terms: D000368:Aged; D002828:Choristoma; D006801:Humans; D008297:Male; D010614:Pharynx; D013961:Thyroid Gland