Chromogranin A (CGA) is a protein found in and released from neuroendocrine cells. The Chromogranin A test is used as a tumor marker. It may be ordered in combination with or in place of serotonin to help as an aid to diagnose carcinoid syndrome. Typical carcinoid symptoms include:
• Abdominal pain
• Valvular heart disease
Measurement of Chromogranin A is also useful as a tumor marker for adrenal tumors as well as small cell lung carcinoma.Fasting is not required for this test. Take all medications as prescribed.