Duodenal Mass Lesions - Differential Diagnosis - Prolapsing Gastric Polyp - Heterotopic Gastric Mucosa - Brunner Gland Hyperplasia - Lymphoid Nodular Hyperplasia - Flexural Pseudopolyp - Duodenal Polyp - Villous Adenoma - Ampullary Carcinoma - Enteric Duplication Cyst - Lipoma - Metastases - Gastrointestinal Stromal Tumor (GIST) - Annular Adenocarcinoma - Lymphoma (aneurysmal dilatation) Dr. Johnny Stewart @DrJonnys #Duodenal #Mass #Lesions #Differential #Diagnosis