Diagnostic Value of Plasma Chromogranin A for Detection of Pheochromocytoma among Adrenal Incidentaloma Patients
Issue: 2/2011
Author: Vladimir Vasilev, Joanna Matrozova, Atanaska Elenkova, Georgi Kirilov, Sabina Zacharieva
Abstract:
Background: Adrenal incidentalomas are defined as incidentally found tumours in the course of abdominal imaging studies performed for reasons unrelated to functional assessment of the adrenal glands and up to 11% of them may be pheochromocytomas. Chromogranin A is a promising marker for the diagnostics and follow- up of neuroendocrine tumours.
Aim of the study: To establish the diagnostic sensitivity and specificity of plasma chromogranin A for the identification of neuroendocrine tumours among patients with adrenal incidentalomas.
Patients and methods: Data from 46 patients with adrenal incidentaloma, 10 patients with pheochromocytoma and 37 healthy individuals were used. Chromogranin A was measured using radioimmunologic method.
Results: Statistically significant difference was found between the levels of chromogranin A in the three study groups – 16,88 ± 14,34 vs 5,36 ± 1,96 vs 4,34 ± 1,39 nmol/l (p<0,001) in patients with pheochromocytomas, adrenal adenomas and healthy subjects respectively. By using data from the control group and ROC analysis the cut-off value for chromogranin A was set at 6,5 nmol/l, demonstrating 100% sensitivity and 81% specificity for pheochromocytoma detection among patients with adrenal incidentaloma.
Conclusions: Chromogranin A is an effective marker for the identification of pheochromocytomas among adrenal incidentaloma patients. Increased levels in non-functioning adenomas require further investigation.
