Pnet

Pnet is an acronym used in different fields, most commonly in medicine and oncology, where context determines its meaning. In medical literature, pNET (often written with lowercase p and uppercase NET) most often refers to pancreatic neuroendocrine tumors, a distinct class of neoplasms arising from neuroendocrine cells in the pancreas. The term can also reflect specific tumor subtypes or related entities depending on capitalization and context.

Pancreatic neuroendocrine tumors are rare neoplasms that originate from pancreatic islet cells. They can be functional, producing hormones such as insulin, gastrin, glucagon, or vasoactive intestinal peptide, which may cause distinct clinical syndromes. Nonfunctional pNETs do not secrete active hormones and are frequently discovered incidentally or due to mass effect. Diagnosis combines imaging (such as CT or MRI), endoscopic ultrasound, and histopathology, with immunohistochemical markers (for example chromogranin A, synaptophysin) used to confirm neuroendocrine differentiation. Hormonal testing may be employed when a functional syndrome is suspected. Tumor grade (based on mitotic rate and Ki-67 index) and stage guide prognosis and treatment.

Management ranges from surgical resection for localized disease to systemic therapies for advanced cases. Targeted therapies (such as everolimus or sunitinib), peptide receptor radionuclide therapy (PRRT), somatostatin analogs for symptom control, and cytotoxic chemotherapy are used depending on tumor grade, functional status, and extent. Prognosis varies with grade and stage, with well-differentiated, low-grade pNETs generally having a more favorable outlook than high-grade or metastatic disease.

Other uses of the acronym include peripheral primitive neuroectodermal tumors (PNETs), a separate category of aggressive soft tissue or bone tumors. Context is essential to distinguish between these meanings.