A Vanishing Polyp: A Large Ileal Lipoma Causing Ileocolic Intussusception.

Area of Science:

• Gastroenterology
• Surgical Pathology

Background:

• Intussusception, the invagination of one gastrointestinal segment into another, is uncommon in adults.
• Adult intussusception is frequently associated with polyps or tumors as underlying causes.

Observation:

• A 55-year-old man presented with abdominal pain, altered bowel habits, and weight loss.
• Colonoscopy revealed a large ascending colon polyp that disappeared during proximal intubation.
• CT scan and repeat colonoscopy identified a lipomatous polyp in the distal ileum.

Findings:

• Histological examination confirmed the polyp as an ileal submucosal lipoma.
• The case uniquely demonstrated intussusception caused by an ileal lipoma, which spontaneously reduced during colonoscopy.

Implications:

• This case expands the understanding of intussusception etiologies in adults.
• It highlights the diagnostic challenge of 'vanishing' lesions and the importance of comprehensive imaging and endoscopic evaluation.
• Submucosal lipomas should be considered in the differential diagnosis of adult intussusception, even when the lesion appears transiently.