The differential diagnosis of the focal lesions in the region of the pancreas is difficult due to the similarity of clinical and radiological pictures of neoplastic and non-neoplastic lesions. This paper presents the most common causes of errors in ultrasound diagnosis of pancreatic pathologies. Attention was paid to the errors resulting from the structural variants of the pancreas and those caused by the neighborhood of intestine, stomach and other organs or vessels. Moreover, the article presents mistakes in the interpretation of ultrasound images of normal pancreas as well as its inflammatory and neoplastic lesions. The errors and mistakes in question were divided into three categories: 1) mistakes related to the anatomical structure of the pancreas (anatomical variants, echostructure and echogenicity, course of the splenic artery); 2) mistakes related to anatomical structures localized in the vicinity of the pancreas (caudate lobe of the liver, other organs and intestinal loops surrounding the head of the pancreas, vessels and bile ducts, lymph nodes in the region of the pancreas or duodenal diverticula and tumors); 3) mistakes related to the pathologies of the pancreas (inflammatory and neoplastic lesions including differentiation between inflammatory tumors and malignant masses). In spite of the progress of imaging techniques, the differential diagnosis of focal solid lesions remains the prime
problem of imaging examinations of the pancreas. The major aim of the ultrasound examination is early detection of pancreatic neoplasm. Improper performance of the examination or a failure to perform a repeated scan when the conditions for the assessment of the pancreas are not favorable or, what is worse, description of normal pancreas when it is not clearly and entirely visible, constitute errors.