Giant Tubulovillous Adenoma of the Small Bowel as an Incidental Finding

ABSTRACT Tubulovillous adenoma (TVA) is a benign epithelial neoplasm typically found in the colon and rectum. While duodenal TVA is uncommon, it poses a significant risk of malignant transformation. When present, duodenal TVA is usually small and often associated with genetic syndromes. We report a rare case of a 58-year-old man with chronic hepatitis B infection who was incidentally found to have a giant TVA of the small bowel. The patient was admitted for healthcare-associated pneumonia and uncomplicated cystitis when he was incidentally found to have a small intestine mass on imaging. Further workup demonstrated a large, circumferential polypoid mass extending from the second and third portions of the duodenum into the proximal jejunum. Endoscopic biopsy confirmed a TVA without a report of malignant transformation. Given the size and location of the lesion, surgical resection was initially planned. This case represents the largest duodenal TVA reported in literature highlighting the importance of early detection.