CHROMOGRANIN – A

Chromogranin A (CgA)

What it is

The Chromogranin A (CgA) test measures the level of chromogranin A, a protein secreted by neuroendocrine cells throughout the body. Elevated levels of CgA are often associated with neuroendocrine tumors (NETs), such as carcinoid tumors, pheochromocytomas, and pancreatic neuroendocrine tumors. It is measured in serum or plasma.

Uses

This test is primarily used as a tumor marker for the diagnosis and monitoring of neuroendocrine tumors. It helps in assessing disease progression, response to therapy, and recurrence after treatment. It may also be used in conjunction with imaging and other biomarkers for comprehensive evaluation of neuroendocrine activity.

Symptoms That May Lead to the Test

Doctors may recommend this test if you experience symptoms suggestive of neuroendocrine tumors, such as unexplained flushing, diarrhea, wheezing, abdominal pain, palpitations, or unexplained weight loss. It is also often ordered in patients with suspected carcinoid syndrome or adrenal gland tumors like pheochromocytoma.

Abnormal Results

High Chromogranin A: Strongly associated with neuroendocrine tumors, but levels can also be elevated in other conditions such as chronic atrophic gastritis, inflammatory bowel disease, liver disease, renal insufficiency, and with proton pump inhibitor (PPI) use. Therefore, interpretation requires clinical correlation.

Normal Chromogranin A: Suggests the absence of a detectable neuroendocrine tumor. However, not all NETs secrete chromogranin A, so a normal result does not completely rule out disease.

Risks