Neuroendocrine cells are specialized cells that function as part of both the nervous and endocrine systems of the body. They are normally found throughout the body.
Tumours made up of neuroendocrine cells are called neuroendocrine tumours. There are many different types of neuroendocrine tumours and the name of the tumour depends on the location in the body and the way the tumour looks when examined under the microscope. Types include include carcinoid tumour, well differentiated neuroendocrine tumour, and neuroendocrine carcinoma.
Carcinoid is a name given to tumours made up of neuroendocrine cells that start in the lung. Although this name is still used, some pathologists now call these tumours neuroendocrine tumours.
Cancers made up of neuroendocrine cells are called neuroendocrine carcinoma. In some areas of the body, neuroendocrine carcinoma is divided into two types based on the size and shape of the cancer cells in the tumour. For example, tumours made up of small cells are called small cell neuroendocrine carcinoma while those made up of large cells are called large cell neuroendocrine carcinoma.
Some tumours can start to look like a neuroendocrine tumour even through they are not made up of neuroendocrine cells. Pathologists describe this as neuroendocrine differentiation.
Pathologists can perform a test called immunohistochemistry to identify these cells under the microscope. Pathologists usually look for three proteins called synaptophysin, chromogranin, and CD56 which are made by both normal neuroendocrine cells and tumours made up of these cells.
Pancreas – Well differentiated neuroendocrine tumour