Pathology dictionary -
Neuroendocrine cells are a special type of cell found throughout the body. They receive information directly from their surroundings and from the nervous system and send messages back by releasing hormones and other chemicals into the body.
Tumours made up of neuroendocrine cells are given different names depending on their location in the body and the way they behave. For example, tumours in the lung that have only a low risk of spreading to other parts of the body are called carcinoid tumours.
Cancers (malignant tumours) 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.
A test called immunohistochemistry can be performed to show that cells are neuroendocrine cells. Pathologists usually look for three proteins called synaptophysin, chromogranin, and CD56 which are made by both normal neuroendocrine cells and neuroendocrine cells in tumours.
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. Immunohistochemistry may be performed to show that these cells are producing synaptophysin, chromogranin, or CD56.