Chromogranin



Chromogranin is a family of proteins primarily found in neuroendocrine cells—specialized cells that release hormones into the blood in response to signals from the nervous system. The main types are chromogranin A, B, and C. These proteins play a crucial role in the storage and release of hormones.

Why do pathologists test for chromogranin?

Pathologists test for chromogranin to help identify and diagnose neuroendocrine tumors—growths originating from neuroendocrine cells. Detecting chromogranin in tissue samples can confirm the presence of these tumors and assist in determining their type and origin.

How do pathologists test for chromogranin?

Pathologists use immunohistochemistry to test for chromogranin. In this process, they apply specific antibodies to a thin tissue slice on a microscope slide. If chromogranin is present, the antibodies bind to it, causing the cells to change color. Cells that change color are described as “positive,” indicating they contain chromogranin. Cells without color change are “negative.”​

Immunohistochemistry for chromogranin. Cells producing the protein are brown in this image.
Immunohistochemistry for chromogranin. Cells producing the protein are brown in this image.

What types of normal cells and tissues will be positive for chromogranin?

Normal cells that typically test positive for chromogranin include:​

  • Neuroendocrine cells in the gastrointestinal tract: Cells in the stomach, small intestine, and large intestine that secrete hormones like serotonin and gastrin.

  • Pancreatic islet cells: Cells in the pancreas, particularly beta cells, which produce insulin.

  • Adrenal medulla cells: Cells in the inner part of the adrenal gland that release adrenaline and noradrenaline.

  • Pituitary gland cells: Various hormone-producing cells in the pituitary gland.

  • Thyroid C cells: Cells in the thyroid gland that produce calcitonin, a hormone involved in calcium regulation.

What types of tumors will be positive for chromogranin?

All tumours that arise from neuroendocrine cells can express chromogranin because these cells naturally contain chromogranin as part of their normal function in storing and releasing hormones.

Tumors commonly positive for chromogranin include:

Identifying chromogranin in these tumors helps pathologists confirm their neuroendocrine origin, ensuring accurate diagnosis and appropriate treatment.

A+ A A-