Case Report: Duodenal duplication: A case report of a rare gastrointestinal anomaly

Highlights

Duodenal duplication is an uncommon congenital anomaly with diverse and nonspecific symptoms, often challenging to diagnose, especially in adolescents.

Surgical excision is the primary treatment, with total removal being ideal, though subtotal resection or digestive bypass may be necessary in complex cases.

Introduction

Duodenal duplication is a rare congenital anomaly involving the formation of a duplicated segment along the gastrointestinal tract, typically located in the small intestine, and even more rarely in the duodenum.¹ These duplications are typically diagnosed in infancy or early childhood due to symptoms like abdominal pain, vomiting, or signs of obstruction; however, they may go undetected into adolescence or adulthood if symptoms are mild or absent.

The absence of specific symptoms in some cases, as well as the overlap with other more common gastrointestinal conditions, can make diagnosis challenging. Imaging studies, such as ultrasound, CT, or MRI, are essential tools for identifying the location, size, and relationship of the duplication with surrounding structures, especially when there is no clear communication with the duodenal lumen.²

In this case, we report a particularly rare occurrence of cystic duodenal duplication diagnosed in an adolescent male, who presented with mild, nonspecific symptoms. This report highlights the importance of a thorough diagnostic process and careful consideration of differential diagnoses in similar cases, offering valuable insights for healthcare providers. This report was written following the CARE guidelines.³

Case report

A 14-year-old male patient was referred to our clinic after experiencing mild vague epigastric pain for three months with no other associated symptoms. There was no history of vomiting, anorexia or change in bowl movements.

A computed tomography (CT) of the abdomen was performed, revealing a well-defined, rounded, inter-duodeno-pancreatic cystic formation measuring 65 × 55 mm and extending 75 mm in height. This mass makes contact with the inferior vena cava and the right renal vein, both of which are patent. There was no apparent communication with the main bile duct and no dilation observed in the intrahepatic or extrahepatic bile ducts ( Figure 1). To further substantiate the diagnosis a magnetic resonance imaging (MRI) showed an inter-duodeno-pancreatic cystic mass with hypo intensity on T1 and hypersignal on T2, homogenous, without apparent diffusion hyperintensity, and no evident duodenal communication. It imposes a mass effect on the cephalic pancreas and displaces the duodenum upward and outward ( Figure 2).

Figure 1. CT image of a well-defined, rounded, inter-duodeno-pancreatic cystic formation measuring 65 × 55 mm and extending 75 mm in height.

Figure 2. MRI image showing an inter-duodeno-pancreatic cystic mass with hypersignal on T2, homogenous, without apparent diffusion hyperintensity, and no evident duodenal communication.

It imposes a mass effect on the cephalic pancreas and displaces the duodenum upward and outward.

The patient underwent an open abdominal exploration by midline incision. Upon exploration, a cystic formation involving the second duodenum (D2) was found, it was closely in contact with the right renal vein and the inferior vena cava ( Figure 3).

Figure 3. Cystic formation involving the second duodenum (D2).

Due to the difficulty in identifying the boundaries of the cystic formation, an upper gastrointestinal endoscopy ( Figure 4) was performed in the operating room. A duodenotomy was then performed on the anterior side of D2, revealing a 7 cm cystic formation protruding and connecting to the inner edge of D2.

Figure 4. Upper gastro intestinal endoscopy showing a communicating duodenal cyst.

The decision was made to perform a cholecystectomy and introduce a trans cystic drain to locate the papilla. The drain was palpated inside the duplication. The latter communicates with the duodenal lumen through a small foramen ( Figure 5). Subsequently, a subtotal resection of the duplication wall was performed, and the duodenotomy was transversely closed, creating a wide internal cysto-duodenostomy.

Figure 5. Subtotal duodenal cyst excision.

The post operative course was uneventful.

Discussion

Duplication cysts, also known as alimentary tract duplications, are congenital lesions of the gastrointestinal (GI) tract. Although the exact cause still eludes us, multiple theories have been put forward to explain its occurrence.¹

In terms of epidemiology, alimentary tract duplications occur in approximately 1 in 4500 births, showing slight male predominance.⁴ These are typically identified in childhood, with most duplications causing symptoms during the initial two years of life. Nevertheless, instance of late presentation in adulthood are also observed.⁵

GI duplications are most frequently found in the distal ileum, with subsequent occurrences in the esophagus, colon, and jejunum. The duodenum accounts for a mere 2%~7% of GI duplications. ⁶

The diagnosis of duodenal duplication (DD) typically takes place during infancy and childhood, a meta-analysis of 47 DD cases revealed that 40,4% occurred in the pediatric period, surpassing the 30,8% found in individuals older than 20. The lowest incidence was observed in the second decade at 21,3%. ⁷

Diverse clinical manifestations have been recorded. Predominantly, patients manifest a discernible abdominal mass, signs of intestinal obstruction, or abdominal discomfort. In certain cases, the occurrence of ectopic gastric mucosa may precipitate ulceration, hemorrhage, and prospective perforation.⁸ In our case the patient was asymptomatic and the duplication was discovered while performing an abdominal CT for mild epigastric pain.

It is also important to mention that a duodenal duplication cyst may exhibit symptoms resembling a type III choledochal cyst, also referred to as choledochocele.² This uncommon condition involves abnormalities in the distal bile duct and ampullary structures, protruding into the duodenal lumen, mimicking the appearance of a duodenal mass. Despite the challenges in distinguishing between these conditions, it is crucial for proper surgical planning.

DDs have traditionally been addressed through surgical means. The surgical approach is determined by the cyst wall’s relationship with the biliary and pancreatic drainage systems. The main objective of surgery is to ensure unimpeded cyst drainage into the duodenum while safeguarding the integrity of the biliary and pancreatic ducts. However, in cases where the proximity of DD to the pancreaticobiliary system poses challenges and risks, an endoscopic procedure emerges as a viable alternative.^9,10

Conclusion

Duodenal duplication, a seldom-discussed congenital anomaly in adolescents, presents diverse clinical manifestations, posing a diagnostic challenge, even for expert clinicians, due to the absence of specific signs and symptoms. Here we reported a particularly rare instance of an adolescent diagnosed with cystic duodenal duplication. This case report serves as valuable guidance for healthcare providers, facilitating early diagnosis and optimal therapeutic decision-making in similar cases.

Reporting guidelines

Zenodo: Duodenal Duplication: A Case Report of a Rare Gastrointestinal Anomaly, https://doi.org/10.5281/zenodo.15623271 ¹¹

This project contains the following underlying data:

CARE checklist

Data is available under Creative Commons Zero v1.0 Universal license.

Ethical approval

Ethical approval was not required.

Consent to publish

Written informed consent was obtained from the patient for publication of this case report. A copy of the written consent is available for review by the editor-in-chief of this journal on request.