CT: computed tomography; mets: metastases; ERCP: endoscopic retrograde cholangiopancreatography; MRCP: magnetic resonance cholangiopancreatography; FNA: fine-needle aspiration; EUS: endoscopic ultrasound; CA 19-9: carbohydrate antigen 19-9; IgG4: immunoglobulin G4; MDCT: multidetector row computed tomography. * If the clinical suspicion for malignancy is high, obtaining an EUS is reasonable to exclude a small pancreatic cancer. ¶ Based on symptomatology and the appearance of the mass or stricture.