title: Primary aldosteronism: functional histopathology and long-term follow-up after unilateral adrenalectomy.
abstract: OBJECTIVE
  To investigate the long-term outcome after unilateral adrenalectomy in patients with primary aldosteronism (PA) and to establish the role of functional pathology for the final diagnosis of aldosterone-producing adenoma (APA) or hyperplasia.
  
  
  METHODS
  A single-centre, retrospective cohort study in a hospital setting.
  
  
  METHODS
  Consecutive patients with PA, n = 120, who underwent unilateral adrenalectomy between 1985 and 2010. Preoperative and postoperative data were analysed. To indicate the site of aldosterone secretion in the resected adrenal, we added functional methods to routine histopathology, using in situ hybridization and immunohistochemistry to detect the presence of enzymes needed for aldosterone (CYP11B2) and cortisol (CYP11B1, CYP17A1) synthesis.
  
  
  RESULTS
  The median follow-up was 5 years and the cure rate of PA 91%. Hypertension was improved in 97% and normalized in 38%. Functional histopathology changed the final diagnosis from APA to hyperplasia in 6 cases (7%). Five of these had no expression of or staining for aldosterone synthase in the adenoma, but only in nodules in the adjacent cortex. All except one APA patient were cured of PA. They had lower preoperative serum potassium and higher 24-h urinary aldosterone than patients with hyperplasia. Among patients with hyperplasia 16 of 26 were cured.
  
  
  CONCLUSIONS
  Most patients were cured of PA by unilateral adrenalectomy. Almost all noncured benefitted from the operation as the blood pressure improved. Functional histopathology proved helpful in the distinction between APA and hyperplasia, and we recommend that functional histopathology should be added to routine histopathology to improve the diagnostic evaluation and aid in tailoring the follow-up.
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Internal Medicine, Division of Endocrinology, Södersjukhuset, Stockholm, Sweden.
authors.forename: Cristina
authors.initials: C
authors.lastname: Volpe
authors.forename: Bertil
authors.initials: B
authors.lastname: Hamberger
authors.forename: Anders
authors.initials: A
authors.lastname: Höög
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Mukai
authors.forename: Jan
authors.initials: J
authors.lastname: Calissendorff
authors.forename: Hans
authors.initials: H
authors.lastname: Wahrenberg
authors.forename: Jan
authors.initials: J
authors.lastname: Zedenius
authors.forename: Marja
authors.initials: M
authors.lastname: Thorén
mesh_terms: D000236:Adenoma / Q000378:metabolism* / Q000601:surgery; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000378:metabolism / Q000601:surgery; D000315:Adrenalectomy; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000737:chemistry; D019405:Cytochrome P-450 CYP11B2 / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006761:Hospitals; D006801:Humans; D006854:Hydrocortisone / Q000737:chemistry; D006929:Hyperaldosteronism / Q000150:complications*; D006965:Hyperplasia / Q000378:metabolism*; D006973:Hypertension / Q000150:complications; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013252:Steroid 11-beta-Hydroxylase / Q000097:blood; D013254:Steroid 17-alpha-Hydroxylase / Q000097:blood; D055815:Young Adult
chemical_list: D000450:Aldosterone; C501892:CYP17A1 protein, human; D013254:Steroid 17-alpha-Hydroxylase; D019405:Cytochrome P-450 CYP11B2; D013252:Steroid 11-beta-Hydroxylase; D006854:Hydrocortisone