EP602 - Intestinal duplicate cyst; a rare disease without clear clinical guidelines. What is the best treatment

Purpose/Background: Ileal duplicate cysts is a rare congenital anomaly, frequently affecting pediatric population, occurring 1 in 100,00 live births. This condition can mimic presenting symptoms of intussusception, acute appendicitis, small bowel obstruction or gastrointestinal hemorrhage. Due to rarity of the disease and lack of established guidelines, treatment algorithm continues to be controversial. In this case report and literature review, we aim to delineate best treatment steps to aid clinical guidelines.

Methods/Interventions: 32 -year- old male otherwise healthy that presented with acute onset abdominal pain, a CT scan abdomen pelvis revealed acute appendicitis and subtle right lower quadrant inflammation (image 1). Patient underwent laparoscopic appendectomy, at this time ileal duplicate cyst was identified and was not resected, pathology of appendectomy revealed diverticulum in appendix and acute appendicitis. The patient recovered from the appendicitis without incidents. At 4 months a diagnostic colonoscopy ruled out further duplication or malignancy. A laparoscopic ileocecectomy with primary anastomosis was performed, revealing benign small intestinal mucosa with serosal fibrous adhesions, without malignancy or ectopic tissue in the duplicated ileum (Figures 2, 3).

Results/Outcomes: Intestinal duplication is rare and commonly found in pediatric population before the age of 2 in up to 80% of cases. When a duplication is found in adults it is as an intraoperative finding, a malignancy or incidental finding on imaging.

There are many hypotheses of why duplication happens:

1. The split notochord: a traction diverticulum is created when the notochord and endoderm split resulting in enteric duplication.

2. Failure of recanalization of the Bowel

3. Abortive twinning, incomplete split in the primitive streak.

Histological architecture of the cyst, could be benign ; with ectopic mucosa including gastric, pancreatic, transitional, or columnar or normal small bowel lining. Malignant transformation is more common in cecal duplication(67%)and includes; Adenocarcinoma, squamous cell carcinoma, Gastrointestinal stromal tumors and neuroendocrine tumors.

There are potential complications including; bowel ischemia, bowel obstruction, bleeding, volvulus and rarely perforation of the cyst itself.

After the duplication is found intraoperatively or as an incidental finding depending on the location we recommend; performing a diagnostic colonoscopy with ileoscopy to rule out malignant degeneration, further duplication, or presence of a fistula.

Surgical resection would be next step, if the lining of the cyst is not malignant a bowel resection, ileocecectomy with primary anastomosis would be sufficient, if there is malignant degeneration, formal oncological resection is indicated.

Due to the rarity of the disease performing a clinical trial would be challenging, the proposed algorithm is based on the analysis of cases reports.

Conclusion/Discussion: Ileal duplicate cysts are a rare disease that usually presents in the pediatric population. When it presents in adults it is commonly an intraoperative finding. No clinical guidelines exist for the treatment in the adult population. Understanding the anatomical implications and associated anatomical anomalies with duplication cyst, such as potential for malignant transformation, is paramount to establish a comprehensive treatment algorithm.

Formal manuscripts are needed and description in surgical textbooks to guide physicians in rare challenging diagnosis.

Figure 2
Duplicated ileum
Figure 1
CT duplicate cyst