Normal variations in the lateral contour of the head and neck of the pancreas mimicking neoplasm: Evaluation with dual-phase helical CT

OBJECTIVE. The purpose of this study was to analyze variations in the lateral contour of the head and neck of the pancreas that can mimic pancreatic masses on CT imaging. MATERIALS AND METHODS. We retrospectively reviewed dual-phase helical CT examinations of 119 patients who had no clinical or CT evidence of pancreatic disease, Contour variations of the head and neck of the pancreas were analyzed and were classified according to their anatomic orientation. RESULTS. Forty-one (34.5%) of the 119 patients had discrete lobulations of pancreatic tissue greater than 1 cm lateral to the gastroduodenal or anterior superior pancreaticoduodenal artery. These lobulations showed normal pancreatic density on both predominantly arterial and portal venous phase images. Contour variants of the pancreatic head and neck were categorized as three main types: anterior (type I), posterior (type II), and horizontal (type III), In the 119 patients, we found 12 type 1 Variants (10%), 23 type II variants (19%), and six type III variants (5%). CONCLUSION. Variations in the lateral contour of the normal head and neck of the pancreas are common. Recognition of the different types of contours may help avoid misinterpretation of normal variants as pancreatic masses.