Arteriovenous malformation that caused prolapse of the colon and was treated surgically in an infant: a case report

BACKGROUND: Various terms have been used to describe vascular lesions in the intestine, including angiodysplasia, arteriovenous malformation, and telangiectasia. Such lesions are common in adults and are typified by angiodysplasia, a type of arteriovenous malformation. In contrast, these lesions are rarely seen in the pediatric population. Angiodysplasia may cause gastrointestinal bleeding, which is sometimes an indication for treatment. Considering the high rate of recurrence after surgical treatment, conservative treatments are mainly chosen. We herein report an extremely rare case of a prolapsed colon due to an arteriovenous malformation successfully treated by resection in a 1-year-old girl. We also highlight the differences between pediatric and adult cases. CASE PRESENTATION: A girl developed bloody stools at 7 months of age. She visited another hospital at 1 year of age because of continuing moderate hematochezia and recent onset of rectal prolapse. Colonoscopy showed a protruding lesion located 15 cm from the anal verge, suggesting a submucosal vascular abnormality. Contrast-enhanced computed tomography and magnetic resonance imaging at our hospital revealed the localized lesion with dilated blood vessels in part of the sigmoid colon; no other lesions were present in the gastrointestinal tract. Laparoscopic-assisted sigmoidectomy was performed. A subserosal vascular lesion was visualized and resected using end-to-end anastomosis. Pathologic examination of the 2.2 × 2.7-cm segment revealed several abnormally enlarged and ectatic blood vessels in the submucosa extending into the subserosa. The lesion was diagnosed as an arteriovenous malformation. The patient had a good clinical course without recurrence at the 2-year follow-up. CONCLUSIONS: An arteriovenous malformation in the sigmoid colon may rarely cause intussusception and prolapse of the colon. Complete resection is a radical and potentially effective treatment. Computed tomography and colonoscopy were useful for evaluation of the lesion in the present case.