Abdominal cocoon: A rare case report of a small bowel obstruction

Abstract

Introduction: Sclerosing encapsulating peritonitis (SEP), or abdominal cocoon, is a remarkably rare entity. It consists of a fibrous layer or cocoon-like sac encasing, in most cases, the small bowel. The lack of specific symptoms makes preoperative diagnosis challenging.

Case presentation: A 50-year-old patient, with no history of abdominal surgery or medical diseases, was admitted for symptoms of small bowel obstruction. On examination, the patient was underweight with a BMI of 18 kg/m². Vital signs were stable. His abdomen was mildly distended and soft. Abdominal CT scan showed signs in favor of a left paraduodenal hernia with incarcerated small bowel loops. Intraoperatively, the small bowels were encapsulated in a cocoon-like structure formed by thick fibrous tissue associated with multiple adhesions. Careful adhesiolysis with complete resection of the membrane was performed. The postoperative course was uneventful. One year later, the patient was symptom-free.

Discussion: SEP is thought to be a persistent inflammatory disorder due to a cause that remains unidentified. It is divided into two categories based on its etiology: primary and secondary. The most common mode of SEP revelation is bowel obstruction. Because there is no clear consensus on SEP management, the therapeutic approach typically follows the management strategy of bowel obstruction.

Conclusion: SEP is an uncommon cause of bowel obstruction. Preoperative detection can be challenging in the absence of pathognomonic signs. Treatment is based on surgery, specifically entailing complete excision of the cocoon and adhesiolysis.

Keywords: Abdominal cocoon; Case report; Intestinal obstruction; Sclerosing encapsulating peritonitis.

Fig. 1

Preoperative CT scan. (a) Axial view showing the bottle gourd sign with a dilated duodenum (yellow contour) associated with a feces sign (white arrows pointing the air bubbles in the duodenum). (b) Axial view showing the transition zone between the dilated duodenum (white star) and the collapsed jejunum (white circle).

Fig. 2

Intraoperative view. A cocoon-like structure (white arrow) formed by thick fibrous tissue encapsulating the small bowels.

Fig. 3

Preoperative CT scan reviewed after surgery. (a) and (b) axial views, (c) coronal view, and (d) sagittal view showing the cocoon capsule (white arrows). (c) The duodenum (white star) encircling the head of the pancreas (yellow square) is dilated, while the jejunum (white circle) is collapsed.