MyPathologyReport
November 2, 2023

Poorly differentiated neuroendocrine carcinoma (NEC) is a type of cancer made up of specialized neuroendocrine cells. The tumour is described as “poorly differentiated” because the cells in the tumour look very little like normal, healthy, neuroendocrine cells. Poorly differentiated NEC can arise almost anywhere in the body. The most common locations for this type of tumour include the pancreas, colon, small intestine, lung, and bladder. Another name for this type of cancer is poorly differentiated neuroendocrine neoplasm (NEN).

How are poorly differentiated neuroendocrine carcinomas classified?

In most areas of the body, poorly differentiated neuroendocrine carcinomas are divided into two groups called 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.

What does it mean if the tumour is described as metastatic?

The term metastatic poorly differentiated neuroendocrine carcinoma means that the cancer cells that have spread 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.

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.

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