Solid lesions of the body and tail of the pancreas challenge all the diagnostic and technical skills of the modern gastrointestinal surgeon. The information available from modern computed tomography (CT), magnetic resonance (MR), and endoscopic ultrasound (EUS) imaging provide diagnostic and anatomic data that give the surgeon precise information with which to plan an operation and to discuss with the patient during the preoperative visit. A preoperative evaluation includes a thorough history and a pancreas protocol CT scan, supplemented by MR imaging and EUS when needed, to differentiate between the various potential diagnoses. These same modalities can be essential in proper staging in the case of malignant lesions, thus aiding in management decisions. Most lesions ultimately require operative resection, barring metastatic disease, with the notable exception of autoimmune pancreatitis.