Clinicopathological Spectrum of Gastroenteropancreatic Neuroendocrine Tumours- A Series of Ten Cases

Neuroendocrine neoplasms are unique, as many of them are associated with secretory properties and specific syndromes of uncontrolled hormone hypersecretion. Gastroenteropancreatic Neuroendocrine Tumours (GEP-NETs) represent the second most common digestive tract malignancy. Epithelial neuroendocrine neoplasms of the gastroenteropancreatic system are divided into Neuroendocrine Tumours (NETs) and Neuroendocrine Carcinomas (NECs). NETs are classified as G1, G2 and G3 based on their proliferative activity. NECs are further classified into Large Cell NEC (LCNEC) and Small Cell NEC (SCNEC) based on the morphology of the tumour cells. The present case series was aimed to present the histopathological spectrum of NETs of the GEP system with respect to clinical and imaging findings, as well as, the associated role of Immunohistochemistry (IHC) as a supplement to histopathological diagnosis. It consists of 10 cases collected over a two-year period from January 2022 to December 2023 at the State Cancer Institute, Gauhati Medical College, Guwahati, Assam, India. All cases of neuroendocrine neoplasms of the GEP system were included. There were seven resection cases and three biopsy cases. A total of (4/10) 40% of the cases belonged to the 40-50 years age group. A total of 5/10 (50%) cases were of the oesophagus, 2/10 (20%) were of the pancreas, and 20% (2/10) were of the rectum, while 1/10 (10%) was of the stomach. A total of 5/10 (50%) cases were SCNEC, 3 (30%) cases were mixed neuroendocrine non neuroendocrine neoplasms, and 2 (20%) cases were NETs (G1 and G3). GEP neuroendocrine neoplasms are sporadic, but they can be multiple and part of a familial syndrome. Assessment of the location and extent of GEP neuroendocrine neoplasms is crucial for management. Treatment consists of surgery, chemotherapy and somatostatin analogues. Challenges for the future include individualisation of treatment based on clinical and/or biological features and the evaluation of innovative therapies, including immunotherapy.