Pancreatic metastases: CT assessment

Abstract

We report the CT appearance of pancreatic metastases and describe their features in relation to the originating primary tumor. We also discuss some limitations in their differential diagnosis and report some theories explaining the pathogenesis of their occurrence. A total of 20 cases (9 males and 11 females) of pancreatic metastases were diagnosed at staging or follow-up of oncologic patients. All patients were evaluated with CT before and after contrast medium administration and had subsequent pathologic confirmation. In 1 case metastases were located solely in the pancreas; in 6 there was only another metastatic location, and in the remaining 13 there was diffuse spread throughout the body. Two of our patients exhibited a multinodular metastatic involvement of the pancreas, 11 had a solitary nodule or mass, and the remaining 7 had a diffusely enlarged pancreas, without any signs of focal disease. All but one of the solitary lesions measured more than 4 cm. In 2 cases a metachronous malignancy was detected at follow-up. Primary malignancies were located: 6 in the lungs, 2 on the skin (melanomas), 3 in breasts, 2 in the ovaries, 3 in the colon, 1 in the stomach, 2 in the kidney, and 1 the thyroid. Our findings confirm the existence of three patterns of metastatization to the pancreas: large solitary masses, multinodular lesions, and diffuse enlargement of the pancreas without focal signs at CT. In contrast to other studies, the large solitary lesion was our most frequent encounter, therefore making differential diagnosis vs primary cancer difficult. Metastases tended to repeat the imaging pattern of the primary. Nevertheless, we wrongly diagnosed pancreatitis due to a small nondetected metastasis, pseudo-cystic mass as a mucinous cystadenocarcinoma, conglomerate of peripancreatic lymph nodes, and a solitary pancreatic mass diagnosed as primary pancreatic cancer. Thus, when faced with a solitary pancreatic lesion at follow-up, histologic diagnosis is strongly recommended. In 2 cases changes in aspect and size were related to therapy.

Pancreatic metastases: CT and MRI findings

“…The most common, reported in 50-73% of cases, is that of a solitary, localized, wellmarginated mass. A second pattern of multiple pancreatic lesions has been reported in 5-10% of cases, and a third pattern of diffuse metastatic infiltration causing generalized enlargement of the organ in 15-44% of cases (2,12,(15)(16)(17). In this study, the most common type was that of the solitary metastasis, present in 63.6% of patients, followed by the multiple metastases type in 27.3% of patients and the diffuse type in 9% of cases.…”

Usefulness of FDG-PET/CT in the detection of pancreatic metastases from lung cancer

“…Clinical and autopsy data indicate that a wide variety of nonlymphomatous primary tumors may metastasize to the pancreas [1][2][3][4][5][6][7]. In most studies, lung cancer is the most frequent type of malignancy causing pancreatic metastasis (18-27%), followed by renal cell carcinoma, breast carcinoma, colorectal cancer, and hepatobiliary tract cancer.…”

“…Recent reports have documented the value of computed tomography (CT) both in showing the presence of pancreatic metastases and in providing guidance to obtain a defi nitive tissue diagnosis [1][2][3][4][5]. Several of these reports have emphasized the pivotal role of the radiologists fi rst in detecting the pancreatic mass and then in suggesting metastasis as the likely diagnosis.…”

CT in the Differentiation of Pancreatic Neoplasms – Progress Report

“…Other tumors that may cause metastasis in the pancreas are bronchial carcinoma, melanoma, gastric cancer or breast cancer [34][35][36][37][38]. Widespread metastases are often present in these tumors.…”