Chromogranin A (CgA) in adrenal tumours.

Introduction: Adrenal tumours can produce specific hormones and cause characteristic symptoms. The majority of adrenal incidentalomas are clinically silent, but some may be malignant or pose other potential threats to life. Chromogranin A (CgA) is the main, nonspecific marker of neuroendocrine tumours (NET). In the adrenals, CgA is produced by chromaffin cells localised in the adrenal medulla. Therefore its measurement in blood might be used as a screening test for pheochromocytoma after the exclusion of other various causes of an increased CgA level. The aim of our study was to investigate plasma CgA concentration in various adrenal tumours.
Material and Methods: EDTA2K plasma samples were obtained from 195 patients with adrenal tumours and from 50 blood donors. CgA was measured in plasma-EDTA2K by immunoradiometric (IRMA) method.
Results: In the majority of patients with adrenal tumours not derived from neuroendocrine cells (chromaffin cells), except those with significant hypercortisolaemia and some patients with adrenal carcinoma, the plasma CgA concentrations were below the cut-off value. In adrenal tumours derived from chromaffin cells (pheochromocytoma), CgA levels were markedly elevated.
Conclusion: In differential diagnosis of adrenal tumours, non-increased CgA level might be useful initial screening evidence for the exclusion of pheochromocytoma.