title: Comparison of adrenal and extraadrenal pheochromocytomas.
abstract: BACKGROUND
  It is commonly believed that extraadrenal tumors (EAT) of the paraganglion system are more likely to be malignant than adrenal tumors (AT) and carry a poorer prognosis. We analyzed 73 paraganglion tumors (PT) to determine whether EATs are more likely to be malignant or have a poorer prognosis than ATs.
  
  
  METHODS
  A review of patients with PTs at three institutions was performed. Malignant tumors were defined as those that metastasized. Comparison of the frequencies of malignant tumors was performed by chi-squared analysis. Survival distributions were determined by Kaplan and Meier analysis. Comparison of survival distributions was performed by log-rank analysis.
  
  
  RESULTS
  There were 73 patients. There were 51 ATs, of which 24 were malignant, and 22 EATs, of which 11 were malignant (p = 0.82). The 5-year survival rate was 77% for patients with ATs and 82% for patients with EATs (p = 0.29). The 5-year survival rate for patients with malignant ATs was 57%, and 74% for patients with malignant EATs (p = 0.15). There were no significant differences in disease-free survival rates on the basis of tumor site.
  
  
  CONCLUSIONS
  We were unable to demonstrate that EATs are significantly more likely to be malignant than ATs. The survival and disease-free survival rates for malignant ATs and EATs are similar, and among malignant tumors, there may be no prognostic value of the anatomic location.
authors.affiliation: Department of Surgery, Oregon Health Sciences University, Portland 97201.
authors.forename: R F
authors.initials: RF
authors.lastname: Pommier
authors.forename: J T
authors.initials: JT
authors.lastname: Vetto
authors.forename: K
authors.initials: K
authors.lastname: Billingsly
authors.forename: E A
authors.initials: EA
authors.lastname: Woltering
authors.forename: M F
authors.initials: MF
authors.lastname: Brennan
mesh_terms: D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010236:Paraganglioma, Extra-Adrenal / Q000401:mortality / Q000473:pathology / Q000601:surgery; D010673:Pheochromocytoma / Q000401:mortality / Q000473:pathology / Q000601:surgery; D016019:Survival Analysis