Enlargement of the pancreatic head in patients with pancreas divisum.

Pancreas divisum (PD) is a congenital anomaly present in 6-10% of the population. Computed tomography (CT) examinations in eight of 15 patients (53%) with endoscopic retrograde pancreatography (ERCP)-proven PD were interpreted as showing enlargement of the pancreatic head. Two of these had carcinoma, three had pancreatitis limited to the ventral pancreas, and three were normal. Criteria to distinguish nonpathologic enlargement of the pancreatic head due to PD alone from pathologic causes may include homogeneous parenchyma and an absence of other abnormal signs on CT. Because PD may simulate a pancreatic head mass, the radiologist should be familiar with this variant, and ERCP should precede biopsy unless other evidence of malignancy is present.