Insulinoma and Pancreatic Neuroendocrine Tumors (PNETs)

Pancreatic Neuroendocrine Tumors (PNETs) form a diverse group, with insulinoma standing out as a noteworthy subtype. In this blog, we will delve into the intricacies of insulinoma and PNETs, exploring their characteristics, diagnostic criteria, and treatment options.

Understanding Pancreatic Neuroendocrine Tumors

PNETs are predominantly non-functional and often malignant. Insulinoma, the most common functional PNET, can be benign or malignant. Gastrinoma holds the title for the most common malignant functional PNET.

Spotlight on Insulinoma 

Insulinoma, the primary functional PNET, is distributed equally across the pancreas.Typically diagnosed at the age of 45, it manifests as a small, benign, and solitary tumor. While mostly sporadic, 5% of cases are associated with MEN-1, indicating a multiple and malignant nature.

Whipple’s Triad: The Diagnostic Triplet 

A diagnostic triad, Whipple’s criteria for insulinoma diagnosis involves neuroglycopenic symptoms, low plasma glucose (40-50 mg/dL), and symptom relief post-glucose administration.

Clinical Features of Insulinoma 

Neuroglycopenic symptoms include apathy, confusion, and seizures.Sympathetic overactivity symptoms involve fatigue, weakness, and tachycardia.Hypoglycemia-induced frequent eating habits contribute to significant weight gain.Insulinoma, typically painless, presents with a range of neurological and sympathetic symptoms.

Diagnosis and Localization Techniques 

The gold standard for diagnosis is a 72-hour monitored fast.Insulin to glucose ratio > 0.3 indicates insulinoma.Elevated levels of plasma insulin, C peptide, and Proinsulin are diagnostic markers.

Imaging techniques like angiography and portal venous sampling aid in localization, with endoscopic ultrasound being the overall best method.

Treatment Strategies 

Diazoxide is given preoperatively as it is directly toxic to β-islet cells which decrease insulin release and it controls symptoms of hypoglycemia.

Treatment of choice 

If the tumour is located in the head of the pancreas then TOC is enucleation. In case it is present in the body or tail then TOC is distal pancreatectomy. Enucleation should not be done if the tumour is present within 2 cm of the main pancreatic duct because it can lead to injury of duct which can cause fistula.

 Managing Persistent Hyperinsulinism After Surgery 

Post-surgery, persistent hyperinsulinism may require additional interventions.Options include somatostatin analogs, hepatic artery embolization, diazoxide, and chemotherapy.Despite metastatic disease, the median survival after resection for insulinoma is promising at five years.

Conclusion

The world of pancreatic tumors is intriguing when it comes to insulinoma and PNETs. Comprehending their clinical characteristics, diagnostic standards, and therapeutic approaches is essential for prompt and efficient handling. The prognosis for those suffering from these disorders is improving due to scientific developments in medicine, providing hope for a higher standard of living.

Also read: High-Yield GIT, Hepatobiliary and Pancreatic Surgery Questions

Hope you found this blog helpful for your GIT, Hepatobiliary and Pancreatic Surgery preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.