Review Question - QID 210762

A 51-year-old man presents to his primary care physician's office for a 6-week history of fatigue and diarrhea. He says that the diarrhea is frequent, small volume, and contains gross blood. Review of systems is significant for subjective fever and an unintentional 5-pound weight loss. He denies recent travel outside of the United States. His past medical history is significant for IV drug abuse, HIV infection with non-compliance, and osteoarthritis. His family history is significant for Crohn disease in his mother. His temperature is 100.7°F (38.2°C), pulse is 90/min, blood pressure is 129/72 mmHg, and respirations are 16/min. His abdominal exam shows mild right and left lower quadrant tenderness with no rebound or guarding. Laboratory results are significant for a CD4 count of 42/mm^3. Colonoscopy with tissue biopsy will most likely reveal which of the following?