Chromogranin A is a biomarker used primarily to help diagnose which group of tumors?

• A. Lymphomas
• B. Neuroendocrine tumors such as carcinoid syndrome and pancreatic neuroendocrine tumors
• C. Prostate adenocarcinoma
• D. Glioblastoma

Answer: (B)

Chromogranin A is a biomarker produced by neuroendocrine cells, so it’s most useful for diagnosing neuroendocrine tumors such as carcinoid tumors and pancreatic neuroendocrine tumors. In these tumors, secretion of chromogranin A reflects tumor activity, so measuring its level in blood can support diagnosis and help monitor disease burden or response to therapy. It’s not specific, and levels can be influenced by factors like certain medications and kidney function, but it remains a helpful tool for NETs. The other tumors listed do not rely on chromogranin A for diagnosis—lymphomas are not neuroendocrine, prostate cancer is tracked with PSA, and glioblastoma relies on imaging and histology rather than chromogranin A.