Pancreatic neuroendocrine tumors: contemporary diagnosis and management

Abstract

Pancreatic neuroendocrine tumors (PNETs) are neoplasms that arise from the hormone producing cells of the islets of Langerhans, also known as pancreatic islet cells. PNETs are considered a subgroup of neuroendocrine tumors, and have unique biology, natural history and clinical management. These tumors are classified as 'functional' or 'non-functional' depending on whether they release peptide hormones that produce specific hormone- related symptoms, usually in established patterns based on tumor subtype. This manuscript will review pancreatic neuroendocrine tumor subtypes, syndromes, diagnosis, and clinical management.

The impact of failure to achieve symptom control after resection of functional neuroendocrine tumors: An 8‐institution study from the US Neuroendocrine Tumor Study Group

“…Even with generally favorable outcomes, certain subtypes of functional NETs are aggressive, particularly those with noninsulinoma histology. Gastrinomas cause clinical symptoms leading to significant morbidity, and many patients with gastrinomas have metastatic disease at the time of presentation . Even with this more aggressive histopathological tumor type, patients may benefit from surgery with improvement in symptom control and increased survival .…”

“…Functional NETs are comprised of several histological types. In sporadic cases, the most common type is insulinoma, followed by gastrinoma and other types including glucagonoma, VIPoma, and somatostatinoma . Each type is characterized by a discrete secretory phenotype and a predictable clinical syndrome .…”

VIPoma: Mechanisms, clinical presentation, diagnosis and treatment (Review)

“…VIPomas are rare tumours that comprise <10% of all pancreatic endocrine tumors (PETs) with an estimated incidence of 1/10,000,000 individuals per year (3). In total, 95% of VIPomas occur in solitary forms, although they likewise appear on the grounds of multiple endocrine neoplasia type 1 (MEN-1) syndrome (4). In adults, they develop most commonly in the fortieth year of life with a sparse female predominance (male:female ratio of 1:3) (5).…”

“…CT is essential in determining the size, the location of the tumour origin, the involvement of nearby structures, vessels, lymph nodes and the presence of calcification (6). VIPomas >3 cm in diameter can be efficiently recognised by CT scans (4). MRI can obtain neoplasms as small as 1 cm in diameter and are useful for the assessment of spinal tumours (27).…”

“…Often, a combination of these will be favoured: Temozolomide with capecitabine, 5-FU/doxorubicin/streptozocin (FAS), or streptozocin with doxorubicin or 5-FU (60). Systemic chemotherapy with a streptozotocin and 5-FU mixture is a standard procedure for patients with bulky extensive growths together with extrahepatic metastases (4).…”