Neuroendocrine Tumors of the Pancreas

Pancreatic neuroendocrine tumors (pNETs) represent a highly heterogeneous group of endocrine tumors that develop from the islet cells of the pancreas. MEN1, ATRX, DAXX, and mTOR pathway genes are involved in the pathogenesis of pNETs. On histology, the tumor is classified as well-differentiated or poorly differentiated and graded according to mitotic figures and the Ki-67 index. Functioning tumors are rarely malignant, release hormones, and manifest with hormone-based symptoms. CECT, MRI, EUS, PET-CT, and octreotide scintigraphy are used for diagnosis, evaluation of tumor characteristics, resectability, metastasis, and functional status. Incidentally detected tumors less than 2 cm in diameter are managed expectantly. Symptomatic and large tumors over 2 cm require formal resection.