Identifies a protein unique to the dense core granules of neuroendocrine cells and tumors and is present in several elements of the diffuse neuroendocrine system, including anterior pituitary, thyroid perifollicular C cells, parathyroid chief cells, pancreatic islet cells, intestinal enterochromaffin cells and tumors derived from these cells. It is an excellent marker for carcinoid tumors, pheochromocytomas, and paragangliomas, but not as good a marker of high-grade neuroendocrine carcinomas as synaptophysin. Chromogranin immunoreactivity was also demonstrated in thymus, spleen, lymph nodes, fetal liver, neurons, the inner segment of rods and cones, the submandibullar gland, and the central nervous system. Useful in evaluating neuroendocrine tumors.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen typeorOne (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody orderedBlock and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.