Margin-negative limited resection of metastatic pancreatic tumors from rectal cancer preoperatively diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsies: report of two cases.

Pancreatic tumor metastasis from colorectal cancer is very rare. This study evaluated the significance of an endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) and surgical treatment. Case 1 was a 67-year-old male with a history of rectal cancer (6 years ago) and lung metastases (5 years ago) who had two masses in the pancreatic head and body. Case 2 was a 58-year-old male with the history of rectal cancer and simultaneous lung metastasis (7 years ago) who had a mass in the pancreatic body. Imaging studies showed stenosis of the pancreatic duct with distal dilatation in both cases, mimicking primary pancreatic cancer. An EUS-FNAB with immunohistochemical staining made a definitive diagnosis of pancreatic metastasis from rectal cancer. Both patients received margin-negative limited resection, middle-segment-preserving pancreatectomy and distal pancreatectomy, respectively, and were alive 16 and 6 months after pancreatectomy, respectively. An EUS-FNAB is helpful to make a definitive diagnosis of pancreatic metastasis and in determining the subsequent therapeutic approach.