title: Thyroid papillary carcinoma arising in ectopic thyroid tissue within a neck branchial cyst.
abstract: BACKGROUND
  Thyroid gland derives from one median anlage at the base of the tongue, and from the two fourth branchial pouches. A number of anomalies may occur during their migration. These can be in form of ectopic tissues, which are frequently found along the course of thyroglossal duct and rarely in other sites, many of these may develop same diseases as the thyroid gland.
  
  
  METHODS
  A 36-years-old female presented with a 3 month history of left side neck mass. The mass disappeared following aspiration of brown colored fluid, which on cytological examination showed cells with nuclear irregularities that warranted the resection of the lesion. The histology demonstrated a thyroid papillary carcinoma arising within the branchial cyst. Thereafter, the patient underwent a total thyroidectomy with central lymph nodes dissection. Histology showed a multifocal papillary carcinoma with central lymph nodes metastases. Only four cases of primary thyroid carcinomas in neck branchial cyst have been described so far.
  
  
  CONCLUSIONS
  In a lateral cystic neck mass, although rare, occurrence of ectopic thyroid tissue and presence of a papillary thyroid carcinoma should be kept in mind.
authors: Department of Experimental Medicine and Pathology, University of Rome La Sapienza, Rome, Italy. angela.fumarola@uniroma1.it
authors: Angela
authors: A
authors: Fumarola
authors: Pierpaolo
authors: P
authors: Trimboli
authors: Rossana
authors: R
authors: Cavaliere
authors: Iolanda
authors: I
authors: Coletta
authors: Alessandra
authors: A
authors: Veltri
authors: Agnese
authors: A
authors: Di Fiore
authors: Antonio
authors: A
authors: Ciardi
authors: Francesca
authors: F
authors: Piccirilli