(A) Macroscopic duodenal view. (B) A high magnification view of the lamina propria of the small intestinal mucosa demonstrating a lack of definite plasma cells, a feature typical of common variable immunodeficiency (H&E stain, 600× magnification) (Picture contributed by Dr Robert M Najarian, MD, Consultant in Gastrointestinal, Hepatobiliary and Pancreatic Pathology Central Pathologist, Pancreatic Disease Registry and Biorepository, Beth Israel Deaconess Medical Center, Department of Pathology, Boston, Massachusetts, USA.)