title: Double adenomas revisited: nonuniform distribution favors enlarged superior parathyroids (fourth pouch disease).
abstract: BACKGROUND
  A double adenoma (DA) is a recognized clinical entity of primary hyperparathyroidism (HPT) and is presumed to have uniform location distribution. We reviewed our experience with 2-gland parathyroid disease to identify anatomic patterns and implications for surgical management.
  
  
  METHODS
  Clinical characteristics were reviewed for 828 consecutive patients with HPT at 2 endocrine referral centers that practice bilateral neck exploration with intraoperative parathyroid hormone (IOPTH) measurement.
  
  
  RESULTS
  Fifteen percent (127 of 828) of HPT patients demonstrated 2 enlarged glands; 13% (107 of 828), 3- or 4-gland hyperplasia; and 71% (592 of 828), single adenomas. DAs in superior parathyroids affected 57 of 127 (45%) patients, an observed frequency 3-fold higher than expected (P<.001, chi-square test). DAs were larger than normal glands (240+/-575 mg vs 28+/-23 mg, P<.001), and superior parathyroid adenomas were larger than adenomas at other sites (421+/-983 mg vs 202+/-353 mg, P=.002). Technetium 99 metastable (Tc99m)-sestamibi imaging and IOPTH identified DAs correctly in only 5 of 84 (6%) and 19 of 75 (25%) of patients tested, respectively.
  
  
  CONCLUSIONS
  DAs have nonuniform anatomic distribution with predilection for abnormal growth in bilateral superior parathyroids-embryologic remnants of the fourth branchial pouch. Since additional abnormal glands were detected by observation with technetium 99 metastable (Tc99m)-sestamibi imaging and IOPTH rarely aiding detection, unilateral neck exploration may predispose to persistent or recurrent HPT.
authors.affiliation: Department of General Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue/A80, Cleveland, OH 44195, USA.
authors.forename: Mira
authors.initials: M
authors.lastname: Milas
authors.forename: Kristin
authors.initials: K
authors.lastname: Wagner
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Easley
authors.forename: Allan
authors.initials: A
authors.lastname: Siperstein
authors.forename: Collin J
authors.initials: CJ
authors.lastname: Weber
mesh_terms: D000236:Adenoma / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D000368:Aged; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010279:Parathyroid Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D010280:Parathyroid Glands / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000503:physiopathology*; D010282:Parathyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D016105:Parathyroidectomy / Q000379:methods; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi
chemical_list: D017256:Technetium Tc 99m Sestamibi