Clinical History
A 43-year-old female patient presented with post-prandial, right-sided abdominal pain and progressive 20 lb weight loss. Her abdominal imaging revealed a duodenal web, based on the finding of the “wind-sock” sign, present on both the upper gastrointestinal barium series and the contrast-enhanced CT examination. The duodenal web was successfully excised.
Imaging Findings
Small bowel barium series demonstrated “duodenal intussusception without obstruction” affecting the third part of the duodenum (Figure 1).
Because underlying malignancy was considered as a possible lead point for intussusception, the patient was referred to surgical oncology for a diagnostic laparoscopy. The second review of her small bowel barium series and the abdominal CT examinations revealed a large intraluminal diverticulum with a “wind-sock appearance”, stretching from the descending duodenum to the fourth portion of the duodenum, a characteristic finding of a duodenal web (Figures 2 and 3).
Discussion
A. Background:
Duodenal web is a rare congenital anomaly that is primarily diagnosed in infancy. However, the diagnosis is rarely made in adulthood. Adults with duodenal web often present with signs of gastric outlet obstruction [1]. Diagnosis is made either with endoscopy, barium series, or oral contrast-enhanced CT imaging. The windsock sign is an important radiographic finding that can definitively diagnose the presence of an intraluminal duodenal web [2].
B. Clinical Perspective:
The presence of a duodenal web is due to a failure of recanalisation of the duodenum during the 6th to 8th weeks of gestation and frequently coexists with other congenital anomalies [3].
However, the diagnosis may be delayed to adulthood. Adults with duodenal web frequently present with symptoms of gastric outlet obstruction, such as postprandial nausea and vomiting, epigastric pain, and loss of weight [4]. Duodenal webs can also cause complications including obstruction, peptic ulcer disease with or without bleeding [1], and cholangitis or pancreatitis due to its proximity to the ampulla of Vater [2]. Common causes of gastric outlet obstruction in adults include peptic ulcer disease, gastric and pancreatic carcinoma must be ruled out [5].
C. Imaging Perspective:
The diagnosis is made with endoscopy, upper GI barium series, or with oral contrast-enhanced CT imaging. In our patient, the third portion of the duodenum could not be visualised on endoscopy; in such cases, the diagnosis of duodenal web can be missed. However, the presence of the wind-sock sign on upper GI barium series or CT examination is pathognomonic for duodenal web [2]. In particular, the coronal reconstruction feature of a CT examination can reveal the classic wind-sock sign. The “sock” appears as a barium-filled sac contained entirely within the duodenum, representing the intraluminal diverticulum. The characteristic finding on imaging has also been referred to as the “halo sign” due to presence of a thin radiolucent line surrounding the diverticulum [2].
D. Outcome:
The patient underwent a surgical exploration where the diagnosis of the duodenal web was confirmed, requiring excision via duodenotomy. Gross anatomy and histology of the resected specimen confirmed the duodenal web without any evidence of malignancy.
E. Teaching Point:
The windsock sign is an important radiographic finding that can definitively diagnose the nonspecific abdominal symptoms found in adults with the presence of an intraluminal duodenal web. 3-D reconstruction of the CT images could be invaluable in making this unusual diagnosis before subjecting the patient for a rewarding surgical excision.
Written informed patient consent for publication has been obtained.
Differential Diagnosis List
Duodenal web
Peptic ulcer disease causing outlet obstruction
Pancreatic cancer
Caustic ingestion
Gastric bezoars
Duodenal diverticulum
