Metastatic Tumor of the Pancreas: Helical CT Findings

ABSTRACT

PURPOSE: To analyze the helical computed tomographic (CT) findings of distant metastatic tumors to the pancreas and to determine the differential points between these and primary pancreatic carcinomas. MATERIALS AND METHODS: We surveyed 22 patients with metastatic tumor of the pancreas, proven on the basis of clinical and pathological findings. Seventeen patients were men, and five and five were women, and their ages ranged between 36 and 83 years. Their primary conditions were lung cancer (n=15), rectal cancer (n=2), melanoma of the foot, chondrosarcoma of the sacrum, cervical cancer, leiomyosarcoma of the uterus, and ex-tragonadal choriocarcinoma of the mediastinum. We retrospectively reviewed the abdominal helical CT findings, analysing the number, location, size and attenuation of masses, as well as secondary change, which included dilatation of the pancreatic and biliary ducts and invasion of peripancreatic tissue or vessels. We also evaluated the differential findings of primary pancreatic cancer. RESULTS: Sixteen patients had a solitary focal mass, while in five, two masses. were present. Among the 22 patients, low-density nodular masses were present in 21; in the other, in whom multiple metastasis from chon-drosarcoma had occurred, there was dense calcification. The size of metastatic masses varied, ranging from 0.6 to 6 cm in diameter. The pancreatic duct proximal to the mass was dilated in ten cases, while the bile duct was dilated in six. The metastatic masses demonstrated no peripancreatic or vascular invasion, though they showed a discrete margin and contour bulging. CONCLUSION: Single metastasis to the pancreas was most common, and metastatic masses had a discrete margin, with contour bulging. There was no peripancreatic or vascular invasion. If the metastasis involved a single low-attenuated mass, however, with pancreatic or biliary dilatation, it was difficult to differentiate this from primary pancreatic cancer.