Splenic Vein Tumor Thrombosis in a Patient With an Oligometastatic Pancreatic Neuroendocrine Tumor: A Case Report and Literature Review.

The presence of a splenic vein tumor thrombus in patients with well-differentiated pancreatic neuroendocrine tumors is rare and is seldom reported with histopathologic confirmation. Consequently, they pose distinct challenges in preoperative planning, particularly if sinistral portal hypertension is present. We present a patient with a well-differentiated pancreatic neuroendocrine tumor, splenic vein tumor venous thrombus, and oligometastatic disease to the liver, which was managed with upfront cytoreductive surgery and portal venous reconstruction. We achieved an R0 resection, and the patient had an uncomplicated clinical course. At the nine-month follow-up, he had no evidence of disease on surveillance imaging.