title: Mediastinal parathyroid carcinoma.
abstract: OBJECTIVE
  To describe a patient with a mediastinal parathyroid carcinoma and hypercalcemia as well as to compare the features of parathyroid carcinoma with those of hypercalcemia due to other causes of primary hyperparathyroidism.
  
  
  METHODS
  We present a case report and discuss the diagnosis and management of this rare tumor.
  
  
  RESULTS
  In a 44-year-old man, severe hypercalcemia and normal findings on neck exploration led to referral and ultimate detection of an anterior mediastinal mass. Surgical resection and pathologic examination of the mass revealed a cystic parathyroid carcinoma. Subsequently, normalization of serum calcium and parathyroid hormone levels ensued.
  
  
  CONCLUSIONS
  Parathyroid carcinoma as an alternative to the diagnosis of primary hyperparathyroidism should be considered in patients with dramatically increased serum calcium and parathyroid hormone levels at the time of initial examination. The mainstay of therapy for parathyroid carcinoma is complete surgical resection. Accurate preoperative localization of parathyroid carcinoma is helpful, especially in instances of reoperation or hypercalcemic crisis.
authors.affiliation: Division of Endocrinology, Metabolism, Nutrition and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Delaney
authors.forename: R A
authors.initials: RA
authors.lastname: Wermers
authors.forename: G B
authors.initials: GB
authors.lastname: Thompson
authors.forename: S F
authors.initials: SF
authors.lastname: Hodgson
authors.forename: S F
authors.initials: SF
authors.lastname: Dinneen