Metastases to the pancreas and peripancreatic lymph nodes from carcinoma of the right side of the colon: CT findings in 12 patients.

OBJECTIVE: Our objective was to describe the CT findings of metastases to the pancreas from carcinoma of the colon and to discuss the pathways of metastasis based on the anatomic relationship between the mesocolon and the pancreas.
MATERIALS AND METHODS: Clinical features and CT scans of 12 patients who had proved metastases to the pancreas from adenocarcinoma of the colon were retrospectively reviewed to define the characteristics of pancreatic lesions. The primary tumors were in the cecum (three patients), ascending colon (five patients), and transverse colon (four patients). Direct extension of the tumor to the pancreas was excluded. Metastases were diagnosed by aspiration or surgical biopsy.
RESULTS: Seven patients (58%) had obstruction of the bile duct and/or pancreatic duct. Four others had symptoms related to the mass, including pain and gastrointestinal obstruction. In eight patients (67%), metastatic tumors involved the pancreas as a focal mass; in the other four (33%), the masses were lobulated and engulfed the pancreas and were indistinguishable from peripancreatic nodal disease. The masses were hypodense in nine patients (75%) and isodense in three patients (25%). Extra-pancreatic metastatic disease was seen in nine patients (75%).
CONCLUSION: Clinical features and CT findings in patients with pancreatic metastases from carcinoma of the colon are similar to those of primary pancreatic ductal adenocarcinomas. The diagnosis of metastasis should be considered when a patient has a pancreatic mass and a history of colon carcinoma.