Pancreatoblastoma: Imaging findings in 10 patients and review of the literature

PURPOSE: To describe the features of pancreatoblastoma at magnetic resonance (MR) imaging, computed tomography (CT), and ultrasonography (US). MATERIALS AND METHODS: Imaging and surgical findings in 10 patients (age range, 2-20 years; mean age, 6.8 years) with pathologically proved pancreatoblastoma were reviewed for tumor size, organ of origin, definition and quality of tumor margins, tumor heterogeneity, calcification, enhancement, ascites, biliary and/or pancreatic ductal dilatation, local invasion, adenopathy, vascular invasion, vascular encasement metastases, and signal intensity on MR images. Results from 10 CT, seven US, and three MR imaging examinations were reviewed. RESULTS: Five of the 10 tumors were pancreatic; four others appeared to be pancreatic or hepatic. Most had well-defined margins (nine of 10), were heterogeneous (nine of 10), and enhanced (10 of 10). Other findings included calcification (two of 10), biliary and pancreatic ductal dilatation (one of 10), and ascites (three of 10). Hepatic (two patients) and pelvic (two patients) metastases were present. Adenopathy (two patients) and vascular invasion (one patient) were not identified,radiologically, Tumors had low to intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. CONCLUSION: Pancreatoblastoma is typically a heterogeneous tumor with well-defined margins that may appear to arise from the pancreas or liver. It may behave aggressively, with localized vascular or bowel invasion or with widespread metastatic disease. Although it is rare, it should be considered in the differential diagnosis of an upper abdominal mass in a child.