Pathological evaluation and classification of digestive neuroendocrine tumours

Abstract

Neuroendocrine neoplasms (NEN) arise from neuroendocrine cells which are distributed in the mucosa of the gastrointestinal (GI) tract and in the pancreas. There are several diagnostic tools to perform the diagnosis of NEN, including imaging, serological tests and endoscopy, but the diagnosis should be formally confirmed by the pathological investigation. The histological feature of NEN, which is generally characteristic in most cases, at least for well-differentiated NEN, must be confirmed by immunohistochemistry and allows to categorise these tumours as NETs (neuroendocrine tumours) or NECs (neuroendocrine carcinomas) according to the last international WHO classification [5]. This is very important to assess the tumour prognosis and to guide patient therapy.