The Chromogranin-A test is a blood test that measures the level of chromogranin-A in the blood. Chromogranin-A is a protein that is produced by neuroendocrine cells and is released into the bloodstream. The test is primarily used to help diagnose and monitor certain types of neuroendocrine tumors, such as carcinoid tumors, which can produce and release chromogranin-A into the bloodstream. The test can also be used to monitor the effectiveness of treatment and detect recurrence of the tumor. The test is performed on a blood sample, and the results are typically reported as a numerical value that is compared to the laboratory’s reference range to determine if the level of chromogranin-A in the blood is within a normal range or if further investigation is necessary. A healthcare provider may recommend additional tests or imaging studies to confirm a diagnosis or monitor the progression of the tumor based on the results of the test and other factors such as symptoms and medical history.