title: Undescended parathyroid adenomas as cause of persistent hyperparathyroidism.
abstract: BACKGROUND
  Undescended glands are a rare cause of primary and secondary hyperparathyroidism (HPT), but they are more common, however, among patients with recurrent HPT or those who have undergone a failed initial cervical exploration. The currently development of more precise noninvasive imaging techniques has improved the results of preoperative diagnosis of these ectopic lesions.
  
  
  METHODS
  The operative reports of patients undergoing parathyroidectomy at our institution were reviewed to identify patients with an undescended parathyroid gland adenomas. Demographic, clinical, imaging and surgical variables were recorded.
  
  
  RESULTS
  Three patients were included: 2/598 parathyroidectomies performed for primary HPT and 1/93 performed for secondary HPT. One case is presented as jaw tumor syndrome (JTS). All the patients had undergone at least one operation before the definitive focused surgery and represented 6% of our parathyroid reoperations. No significant complications and no recurrences were observed in the long-term follow up.
  
  
  CONCLUSIONS
  Accurate preoperative localization of these lesions was possible with noninvasive studies. High cure rate is possible through selective approach when accurate preoperative localization. Thorough knowledge of parathyroid embryology and meticulous surgical technique are essential, particularly in patients with previous unsuccessful explorations.
authors: Endocrine Surgery Unit, Hospital del Mar, Barcelona, Spain.
authors: Paula
authors: P
authors: Rioja
authors: Endocrine Surgery Unit, Hospital del Mar, Barcelona, Spain.
authors: Germán
authors: G
authors: Mateu
authors: Endocrine Surgery Unit, Hospital del Mar, Barcelona, Spain.
authors: Leyre
authors: L
authors: Lorente-Poch
authors: Endocrine Surgery Unit, Hospital del Mar, Barcelona, Spain.
authors: Juan J
authors: JJ
authors: Sancho
authors: Endocrine Surgery Unit, Hospital del Mar, Barcelona, Spain.
authors: Antonio
authors: A
authors: Sitges-Serra
keywords: Undescended parathyroid adenoma (UPA); parathymus; persistent hyperparathyroidism (HPT); selective surgical approach