title: Risk of concomitant malignancy in hyperfunctioning adrenal incidentalomas.
abstract: BACKGROUND
  Adrenal masses are common incidental findings on radiologic imaging. The association between malignancy and hormonal hyperactivity found in incidentally discovered adrenal tumors, however, remains unclear.
  
  
  METHODS
  A retrospective analysis of prospectively collected data from patients who underwent adrenalectomy for incidentally discovered adrenal tumors at a single institution. Outcomes and operative data were compared by univariate analysis. Area under the curve was used to analyze the effect of tumor size in predicting malignancy.
  
  
  RESULTS
  There were 49 patients who initially presented with adrenal incidentalomas that underwent adrenalectomy. Most patients were Caucasian women with an average age of 51 ± 14 years. Of this group, 24 patients underwent resection for hyperfunctioning adrenal glands. There were no significant differences in malignancy rates between hyperfunctional and nonfunctional tumors (4.1% vs. 12.0%, P = 0.32). On final histopathology, there were four patients with adrenal malignancies: two adrenocortical carcinomas and two metastatic from renal carcinoma. Only one patient with a hyperfunctioning adrenal tumor had underlying malignancy. Overall, invasion of adjacent structures (P < 0.001), presence of lymphadenopathy (P = 0.02), metastasis (P = 0.03), irregular tumor margins (P = 0.01), heterogeneity (P = 0.05), and tumor size >6 cm (P = 0.04) on radiologic imaging were strongly associated with malignancy in adrenal incidentalomas.
  
  
  CONCLUSIONS
  The risk of concomitant malignancy and hormonal hyperactivity in adrenal incidentalomas is very low. Tumor size (>6 cm) and radiographic features remain the most important predictors of adrenal malignancy, regardless of tumor function.
authors.affiliation: Division of Surgical Endocrinology, DeWitt Daughtry Family Department of Surgery, University of Miami Leonard M. Miller School of Medicine, Miami, Florida 33136, USA. ballan@med.miami.edu
authors.forename: Bassan J
authors.initials: BJ
authors.lastname: Allan
authors.forename: Chad M
authors.initials: CM
authors.lastname: Thorson
authors.forename: Robert M
authors.initials: RM
authors.lastname: Van Haren
authors.forename: Punam P
authors.initials: PP
authors.lastname: Parikh
authors.forename: John I
authors.initials: JI
authors.lastname: Lew
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D000310:Adrenal Gland Neoplasms / Q000453:epidemiology* / Q000556:secondary / Q000601:surgery; D000315:Adrenalectomy; D000308:Adrenocortical Hyperfunction / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D033162:Incidental Findings; D007680:Kidney Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Adrenal; Adrenalectomy; Incidentaloma; Malignancy; Predictors