Synaptophysin

MyPathologyReport
October 23, 2023

Synaptophysin is a protein made by neuroendocrine cells. These types of cells are found in the brain and in endocrine organs such as the thyroid gland, adrenal gland, and pancreas. Small groups of neuroendocrine cells can also be found in non-endocrine organs throughout the body such as the stomach, small bowel, colon, skin, bladder, and lungs. The cells in most neuroendocrine tumours will also make synaptophysin.

Cells use synaptophysin to make a specialized piece of cellular machinery called a secretory granule. These secretory granules hold and release chemicals called transmitters and are used to send signals between cells. Synaptophysin is often found with another protein called chromogranin.

Pathologists often perform a test called immunohistochemistry (IHC) to help identify synaptophysin-producing cells in a tissue sample. The protein is normally found in a part of the cell called the cytoplasm or cell body. This test is helpful when trying to decide if the cells being examined are neuroendocrine cells or producing proteins typically made by neuroendocrine cells.

Examples of tumours that are positive for synaptophysin:

• Medullary thyroid carcinoma
• Small cell neuroendocrine carcinoma of the lung
• Large cell neuroendocrine carcinoma of the lung
• Well differentiated neuroendocrine tumour
• Poorly differentiated neuroendocrine carcinoma
• Merkel cell carcinoma
• Carcinoid tumour of the lung
• Adrenocortical adenoma
• Adrenocortical carcinoma
• Paraganglioma
• Pheochromocytoma

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

Other helpful resources

Atlas of pathology