title: Parathyroidectomy for tertiary hyperparathyroidism associated with X-linked dominant hypophosphatemic rickets.
abstract: BACKGROUND
  X-linked dominant hypophosphatemic rickets (XLHR) is a hereditary metabolic bone syndrome that is only beginning to be understood and is rarely associated with progression to irreversible tertiary hyperparathyroidism. We report our surgical experience with 6 patients with XLHR who underwent parathyroidectomy for associated autonomous parathyroid hyperfunction.
  
  
  OBJECTIVE
  Parathyroidectomy can successfully treat tertiary hyperparathyroidism in the setting of XLHR, although an understanding of expected operative findings and postoperative complications is essential.
  
  
  METHODS
  The study group comprised 6 patients with XLHR identified from our endocrine surgery database. Presentation, surgical procedure, parathyroid pathologic findings, and subsequent outcome are outlined.
  
  
  RESULTS
  There were 4 women and 2 men. All were exposed to long-term vitamin D and phosphate supplementation therapy. All had persistently elevated preoperative levels of parathyroid hormone and serum calcium. The patients were treated as follows: 3 had total parathyroidectomy, 2 had 3 parathyroid glands identified and resected, and 1 had 2 abnormal parathyroid glands resected with 2 normal-appearing parathyroid glands left in situ. One patient subsequently required completion parathyroidectomy for recurrent disease. Pathologic examination results revealed hyperplasia of all resected parathyroid glands in 4 of 6 patients. One patient had a single adenoma with 3-gland hyperplasia, and 1 patient had a double adenoma. The principal complication of this procedure was profound symptomatic hypocalcemia requiring intravenous calcium infusion. Hungry bone syndrome was also observed in most subjects. Long-term, all patients achieved normocalcemia.
  
  
  CONCLUSIONS
  Tertiary hyperparathyroidism is a rare but recognized complication of XLHR. Parathyroidectomy effectively treats this complication caused by autonomous parathyroid hyperfunction, but profound postoperative hypocalcemia necessitates careful management.
authors.affiliation: University of Sydney Endocrine Surgical Unit, Royal North Shore Hospital, Sydney, Australia.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Savio
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Gosnell
authors.forename: Solomon
authors.initials: S
authors.lastname: Posen
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Reeve
authors.forename: Leigh W
authors.initials: LW
authors.lastname: Delbridge
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery*; D007015:Hypophosphatemia, Familial / Q000150:complications* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D016105:Parathyroidectomy / Q000379:methods*; D011182:Postoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome