title: Correlations of plasma concentrations of B-cell polypeptides with pathologic features of insulinomas.
abstract: OBJECTIVE
  To assess the correlations between plasma concentrations of b-cell polypeptides (insulin, C peptide) and size, multiplicity, and malignancy of insulinomas.
  
  
  METHODS
  We retrospectively reviewed the medical records of 55 consecutively treated patients at our institution with surgically confirmed insulinoma. The 29 female and 26 male patients ranged from 13 to 77 years of age (median, 46). Plasma insulin, C peptide, proinsulin, and glucose concentrations were analyzed statistically in patients with benign and those with malignant insulinomas.
  
  
  RESULTS
  Significant correlations were observed between plasma insulin and tumor size (r = 0.45; P = 0.001) and tumor volume (r = 0.41; P = 0.007) and between plasma C peptide and tumor size (r = 0.38; P = 0.004) and tumor volume (r = 0.33; P = 0.025). No differences between benign and malignant tumors were noted for plasma insulin, C peptide, glucose, nor tumor size or volume. No correlations were found between plasma insulin, C peptide, or glucose and number of tumors.
  
  
  CONCLUSIONS
  The plasma levels of insulin and C peptide provide qualitative indications about the size of insulinomas.
authors.affiliation: Division of Endocrinology and Metabolism, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Kane
authors.forename: F J
authors.initials: FJ
authors.lastname: Service
authors.forename: P C
authors.initials: PC
authors.lastname: O'Brien
authors.forename: C S
authors.initials: CS
authors.lastname: Grant
authors.forename: J A
authors.initials: JA
authors.lastname: Heerden
authors.forename: G B
authors.initials: GB
authors.lastname: Thompson
authors.forename: J A
authors.initials: JA
authors.lastname: Carney
authors.forename: P C
authors.initials: PC
authors.lastname: Kao