Poorly differentiated neuroendocrine carcinoma is a type of cancer made up of specialized neuroendocrine cells. Poorly differentiated neuroendocrine carcinoma can be found almost anywhere in the body. The tumour is described as “poorly differentiated” because the cells in the tumour look very little like normal, healthy, neuroendocrine cells. Another name for this type of cancer is poorly differentiated neuroendocrine neoplasm (NEN).
Neuroendocrine cells are a specialized type of cell that are found throughout the body. Neuroendocrine cells produce chemicals called hormones that act as a signal to influence the function of nearby cells.
Poorly differentiated neuroendocrine carcinoma is a malignant (cancerous) type of tumour.
Poorly differentiated neuroendocrine carcinomas are commonly found in the pancreas, lungs, small intestine, large intestine (colon), skin, and reproductive organs.
Poorly differentiated neuroendocrine carcinomas are divided into two groups: small cell neuroendocrine carcinoma and large cell neuroendocrine carcinoma. Small cell neuroendocrine carcinoma is made up of relatively small cells with hyperchromatic (dark) nuclei and very little cytoplasm (cell body). In contrast, large cell neuroendocrine carcinoma is made up of much larger cells with open nuclei that contain large clumps of genetic material called nucleoli.
The term metastatic poorly differentiated neuroendocrine carcinoma is used to describe cancer cells that have travelled from the place where the tumour started (the primary tumour) to another part of the body such as a lymph node, the lungs, the liver, or a bone.