An unusual case of a well-differentiated neuroendocrine tumour of the ileum with peritoneal carcinomatosis: a case report

Neuroendocrine tumours (NETs) are a family of neoplasms that come from neuroendocrine cells and express neural markers, such as synaptophysin or chromogranin A. The current classifications of these tumours are presented by the WHO 2000 classification, based on histological parameters, and the WHO 2010 classification, based on the proliferative index, that divides the NETs into a neuroendocrine tumour of a low grade, neuroendocrine tumour of a intermediate grade and neuroendocrine carcinoma (NEC) of a high grade. We are reporting a very rare case of a G1 low-grade neuroendocrine tumour (NET) of the ileum with a peritoneal carcinomatosis. This case is challenging because the tumour expresses low proliferative index as G1 tumours, but it has an aggressive clinical behaviour such as node metastasis and peritoneal carcinomatosis. The peritoneal carcinomatosis is not actually considered by the current classifications of NETs, so it is difficult to predict the prognosis of this patient.