title: Primary hyperparathyroidism patients with positive preoperative sestamibi scan and negative ultrasound are more likely to have posteriorly located upper gland adenomas (PLUGs).
abstract: BACKGROUND
  Standard preoperative imaging for primary hyperparathyroidism usually includes sestamibi scanning (MIBI) and ultrasound (US). In a subset of patients with a positive MIBI and a negative US, we hypothesize that the parathyroid adenomas are more likely to be located posteriorly in the neck, where anatomically they are more difficult to detect by US.
  
  
  METHODS
  We retrospectively reviewed the records of 661 patients treated for primary hyperparathyroidism between 2004 and 2009 at a tertiary referral center. We included patients who for their first operation had a MIBI that localized a single lesion in the neck and an US that found no parathyroid adenoma. We excluded patients with persistent or recurrent hyperparathyroidism, and patients with MIBIs that were negative, that had more than one positive focus, or that had foci outside of the neck. Sixty-six cases were included in the final analysis.
  
  
  RESULTS
  A total of 54 patients (83%) had a single adenoma, 4 (6%) had double adenomas, and 7 (11%) had hyperplasia. Thirty-three patients (51%) had a single upper gland adenoma; 19 of these (58%) were posteriorly located upper gland adenomas (PLUGs). PLUGs occurred more often on the right side than on the left (P = 0.048, Fisher's test). PLUGs were also larger than other single adenomas (mean 1.85 vs. 1.48 cm, P = 0.021, t-test). Seventy-six percent of patients successfully underwent a unilateral or focused exploration. Six patients (9%) had persistent disease, which is double our group's overall average (4-5%).
  
  
  CONCLUSIONS
  Primary hyperparathyroid patients with preoperative positive MIBI and negative US are more likely to have PLUGs.
authors.affiliation: Department of Surgery, University of California, Los Angeles, CA, USA. aharari@mednet.ucla.edu
authors.forename: Avital
authors.initials: A
authors.lastname: Harari
authors.forename: Elliot
authors.initials: E
authors.lastname: Mitmaker
authors.forename: Raymon H
authors.initials: RH
authors.lastname: Grogan
authors.forename: James
authors.initials: J
authors.lastname: Lee
authors.forename: Wen
authors.initials: W
authors.lastname: Shen
authors.forename: Jessica
authors.initials: J
authors.lastname: Gosnell
authors.forename: Orlo
authors.initials: O
authors.lastname: Clark
authors.forename: Quan-Yang
authors.initials: QY
authors.lastname: Duh
mesh_terms: D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000601:surgery; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging* / Q000209:etiology; D011300:Preoperative Care; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi