2016 Volume 49 Issue 8 Pages 738-745
The patient was a 63-year-old woman presenting with a tumor of 6 cm at the head of the pancreas on abdominal US. She was referred to our hospital to receive treatment. It was diagnosed as a pancreatic neuroendocrine tumor based on CT and MRI findings. Endoscopic US showed a continuous tumor shadow in the superior mesenteric vein, giving a suspicion of a tumor thrombus in the superior mesenteric vein. She underwent subtotal stomach-preserving pancreaticoduodenectomy and tumor thrombus extraction through an incision on the superior mesenteric vein. In pathological tissues, neoplastic cells formed cordlike and rosette structures. In immunostaining, the Ki-67 labeling index was positive for 20.5% of the primary tumor site, chromogranin A, synaptophysin, CD56. However, she had no hormone-producing symptom and received a diagnosis of non-functional pancreatic neuroendocrine carcinoma. Since only radical resection achieved long-term survival, the first-line therapy of a pancreatic neuroendocrine carcinoma is surgical resection. Even if the tumor were resected, because of its high grade malignancy, the prognosis of pancreatic neuroendocrine carcinoma with tumor venous thrombus is poor. However, this patient achieved a recurrence-free survival of 31 months.