title: The dangers of parathyroid biopsy.
abstract: BACKGROUND
  We report an unusual case of a 66-year-old female with a suspicious thoracic outlet mass presenting with severe biochemical hyperparathyroidism and classic hypercalcemic symptoms of renal and bone involvement.
  
  
  METHODS
  There was clinical suspicion for parathyroid carcinoma, further supported by intra-operative findings. However, the final pathology described a primary hyperceullar parathyroid lesion with pathognomonic changes secondary to fine-needle aspiration (FNA) biopsy, along with a separate parathyroid lesion likely resulting from seeding along the needle tract. Upon further review, record of a remote FNA was discovered. This case highlights the complications associated with parathyroid FNA resulting in a diagnostic challenge and raising the possibility of malignancy.
  
  
  CONCLUSIONS
  We therefore recommend to take caution when there is a prior parathyroid FNA, as it can present with the risks of a secondary lesion from seeding and increase resemblance of malignancy both clinically and through pathologic diagnosis.
authors.affiliation: Department of Otolaryngology (ENT), Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Joanne
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Otolaryngology (ENT), Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Gilad
authors.initials: G
authors.lastname: Horowitz
authors.affiliation: Department of Otolaryngology (ENT), Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Hong
authors.affiliation: Department of Otolaryngology (ENT), Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Mario
authors.initials: M
authors.lastname: Orsini
authors.affiliation: Department of Pathology, University Health Network (UHN), 200 Elizabeth Street, 11th Floor, Toronto, ON, M5G 2C4, Canada.
authors.forename: Sylvia L
authors.initials: SL
authors.lastname: Asa
authors.affiliation: Department of Otolaryngology (ENT), Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. kevin.higgins@sunnybrook.ca.
authors.forename: Kevin
authors.identifier: http://orcid.org/0000-0001-5760-1390
authors.initials: K
authors.lastname: Higgins
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000009:adverse effects*; D005260:Female; D006801:Humans; D009366:Neoplasm Seeding; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy
keywords: Diagnostic complication; FNA biopsy; Parathyroid; Pathology