title: Nonfunctional parathyroid carcinoma.
abstract: OBJECTIVE
  Nonfunctional parathyroid carcinoma (PTC) is one of the rarest malignant diseases and only nine cases have been reported during the last 23 years. We present a case of nonfunctioning PTC and review the literature in an effort to provide a better understanding of this rare disorder.
  
  
  METHODS
  One patient with nonfunctioning PTC was presented, detailing the clinical features, histologic findings, diagnosis, and treatment. Together with data from the other nine cases reported last 23 years, the related literature is also reviewed.
  
  
  RESULTS
  The presented case was a 47-year-old man with a 2-month history of an enlarging painless cervical mass followed by a 2-week history of hoarseness. Clinical and laboratory evaluations failed to reveal evidence of hyperparathyroidism. Pathological analysis of the resected tumor disclosed findings consistent with PTC. The nonsecretory state of the tumor was further supported by immunoreactivity for parathyroid hormone in tissue, and normal serum levels of this peptide and calcium preoperatively and postoperatively.
  
  
  CONCLUSIONS
  Most nonfunctional PTC is detected late due to a paucity of symptoms, of which a palpable neck mass is the most common. Patients with nonfunctioning PTC appear to have a poorer prognosis than do those with functioning parathyroid cancers.
authors.affiliation: Department of General Surgery, Shanghai Chang Zheng Hospital, Second Military Medical University, 415 Feng Yang Road, 200003 Shanghai, People's Republic of China.
authors.forename: Wen Chao
authors.initials: WC
authors.lastname: Gao
authors.forename: Can Ping
authors.initials: CP
authors.lastname: Ruan
authors.forename: Jun Chu
authors.initials: JC
authors.lastname: Zhang
authors.forename: Hui Min
authors.initials: HM
authors.lastname: Liu
authors.forename: Xin Yun
authors.initials: XY
authors.lastname: Xu
authors.forename: Yan Ping
authors.initials: YP
authors.lastname: Sun
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
mesh_terms: D006801:Humans; D008297:Male; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000175:diagnosis* / Q000601:surgery*