Elevated chromogranin A (CgA) levels can be seen with neuroendocrine tumors, such as carcinoid, gastrinoma, insulinoma, glucagonoma, VIPoma, and somatostatinoma. Elevated gastrin can be seen with various entities including Zollinger-Ellison Syndrome, caused by gastrinoma, which can be found in pancreas and/or duodenum. To localize the tumor, your doctor may decide to order imaging tests, including but not limited to pancreatic protocol CT and/or MRI abdomen with and without contrast (which includes precontrast, postcontrast arterial, and postcontrast venous phase; the arterial phase is key because these tumors tend to be hypervascular).
Not enough info. What kind of infections? Urinary tract infections? All you posted was a normal creatinine level. Any other lab and/or imaging tests?