The Silent Presentation of a Non-functioning Pancreatic Neuroendocrine Tumor: A Case Report.

Pancreatic neuroendocrine tumors (PNETs) are rare pancreatic neoplasms that can be classified as functioning or non-functioning. Non-functioning PNETs are often asymptomatic and detected incidentally. We discuss the case of a 54-year-old female with a past medical history significant for Crohn's disease (CD) who underwent a CT enterography in 2022 for follow-up imaging. At that time, a lesion at the pancreatic tail was discovered, and active surveillance was chosen. Two years later, an ER visit for symptomatic cholelithiasis indicated growth of this lesion via MRI and CT. A subsequent biopsy confirmed a well-differentiated grade 1 non-functioning PNET and accompanying pancreatic cyst. Surgical options were discussed, and the patient underwent distal pancreatectomy with splenectomy, and the tumor was successfully excised. The patient had an uneventful post-surgical course. Non-functioning PNETs are challenging to diagnose due to their subtle symptoms and are often detected at later stages. Imaging modalities like MRI, CT, and endoscopic ultrasound are key in diagnosis. Surgical resection remains the most definitive treatment modality. This report highlights the diagnostic complexity and the potential for varied presentations of non-functioning PNETs, underscoring the need for further research on their characteristics, management, and associations with other pancreatic lesions.