A case of high grade pancreatic neuroendocrine tumor and the importance of endoscopic ultrasound-guided fine needle biopsy technique.

Pancreatic neuroendocrine tumors are an uncommon group of insidious neoplasms that are often diagnosed in the advanced stages. Diagnosing pancreatic neuroendocrine tumors involves proper biopsy technique and immunohistochemistry, while treatments include targeted therapies and systemic chemotherapy. When diagnosed early, patients with localized disease generally have a positive prognosis. We share a case of a 56-year-old man presenting to the emergency department with acute abdominal pain found to have poorly differentiated pancreatic neuroendocrine tumor with metastasis on repeat endoscopic ultrasound-guided fine needle biopsy. Despite multiple treatment changes, sustained tumor presence led to numerous complications and ultimately patient death. This case highlights the nuances and challenges of diagnosing and treating a rare pancreatic neuroendocrine tumor, such as the importance of biopsy technique.