title: A single-institution 25-year review of true parathyroid cysts.
abstract: BACKGROUND
  Parathyroid cysts (PCs) are rare, and their origin is a subject of debate. They have been described as either functional, causing hyperparathyroidism, or non-functional in eucalcaemic patients.
  
  
  METHODS
  We have performed a 25-year departmental review of PCs. Features studied included the clinical presentation and intra-operative findings, and a histological review was performed. Cases of cystic degeneration of parathyroid adenomas and pseudocystic change were excluded.
  
  
  RESULTS
  Over 25 years, 22,009 thyroidectomies and 2,505 parathyroidectomies were performed in our department. Amongst these, 38 non-functional PCs were documented in 37 patients. The mode of presentation included incidental findings on routine chest x-ray, compressive symptoms or an asymptomatic palpable neck mass. Aspiration was the initial treatment in 14 patients and was curative in 10 of these. Four out of 14 patients underwent surgical procedures for recurrence of the cyst that occurred 6 to 48 months after aspiration. In 27 patients, surgery was performed and all identified PCs were localized in the inferior parathyroid glands. Histologically, the cyst wall consisted in associations of lymphoid, muscular, thymic, salivary, adipose and mesenchymal tissues.
  
  
  CONCLUSIONS
  PCs are rare but should be included within the differential diagnosis of a neck lump. True PCs are non-functional. Pathological and immunohistochemical findings are suggestive of a branchial origin. Fine-needle aspiration may be curative and is diagnostic due to the characteristic appearance of the fluid and high PTH levels on assay.
authors.affiliation: Department of Endocrine Surgery, La Timone University Hospital, Marseille, France.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ippolito
authors.forename: F Fausto
authors.initials: FF
authors.lastname: Palazzo
authors.forename: Frederic
authors.initials: F
authors.lastname: Sebag
authors.forename: Mauricio
authors.initials: M
authors.lastname: Sierra
authors.forename: Catherine
authors.initials: C
authors.lastname: De Micco
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Henry
mesh_terms: D000293:Adolescent; D000368:Aged; D044963:Biopsy, Fine-Needle; D002118:Calcium / Q000097:blood; D003560:Cysts / Q000473:pathology* / Q000628:therapy; D005260:Female; D006801:Humans; D007828:Laryngoscopy; D008297:Male; D008875:Middle Aged; D010279:Parathyroid Diseases / Q000473:pathology* / Q000628:therapy; D010280:Parathyroid Glands / Q000601:surgery; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D012086:Reoperation; D012189:Retrospective Studies; D013965:Thyroidectomy
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium