Avicenna Journal of Medicine

: 2013  |  Volume : 3  |  Issue : 4  |  Page : 103--105

Abdominal cocoon

Binit Sureka, Mahesh Kumar Mittal, Mukul Sinha, Aliza Mittal, Brij Bhushan Thukral 
 Department of Radiodiagnosis and Imaging, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India

Correspondence Address:
Binit Sureka
Department of Radiodiagnosis and Imaging, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi - 110 029


Abdominal cocoon is an acquired benign condition in which there is encapsulation of bowel loops by a fibrous membrane. Pre-operative clinical diagnosis is usually difficult. Imaging plays a critical role in timely and accurate diagnosis. We present a brief discussion on this topic with relevant imaging findings.

How to cite this article:
Sureka B, Mittal MK, Sinha M, Mittal A, Thukral BB. Abdominal cocoon.Avicenna J Med 2013;3:103-105

How to cite this URL:
Sureka B, Mittal MK, Sinha M, Mittal A, Thukral BB. Abdominal cocoon. Avicenna J Med [serial online] 2013 [cited 2020 May 27 ];3:103-105
Available from: http://www.avicennajmed.com/text.asp?2013/3/4/103/120502

Full Text


Abdominal cocoon is a rare condition characterized by encapsulation of bowel loops by fibrocollagenous membrane. Previously in 1907, Owtschinnikow described it as "peritonitis chronica fibrosa incapsulata." [1] This entity is more common in females from tropical regions. [2],[3]


Abdominal cocoon also known as sclerosing encapsulating peritonitis was first described by Foo et al. in 1978. [4] It is a benign condition in which there is encasement of the small bowel by a cocoon like sac. The sac is a fibrocollagenous membrane. Predisposing factors for abdominal cocoon formation are history of previous abdominal surgery, peritonitis, chronic ambulatory peritoneal dialysis, infections such as tuberculosis, prolonged use of practolol, liver transplant, biliary tract and gastrointestinal tract inflammation. [5],[6] When the cause is not known it is classified as primary (idiopathic). Clinical diagnostic clues are presentation in a young adolescent girl, non-tender soft mass and intermittent episodes of intestinal obstruction. Two clinical signs, which are important in diagnosing this entity are: "Fixed, asymmetrical distension of the abdomen and difference in the consistency of the abdominal wall to palpation." [7],[8] The flat area is firm, due to the dense fibrous capsule and the distended area soft, due to the thin walled distended small intestine with no overlying fibrous layer. Pathogenesis for abdominal cocoon formation is increased release of fibrogenic cytokines leading to fibrin like material deposition on the peritoneum. [6]

On imaging, plain radiographs may show dilated bowel loops with air-fluid level clustered in the mid abdomen. Barium-meal follow through examination show classical clustering and conglomeration of bowel loops in the center of the abdomen, which remains in same location on delayed films [Figure 1]. Proximal bowel obstruction is usually seen [Figure 2]. Transit time is increased. Cauliflower appearance of bowel loops may be noted due to concertina arrangement of loops. On ultrasonography, echogenic mass of dilated small-bowel loops surrounded by a thick rim of hypoechoic fibrous membrane is seen. On computed tomography (CT), fibrous membrane surrounding the bowel loops is usually seen and is diagnostic [Figure 3] and [Figure 4]. This encapsulation may be partial or complete. Other signs on CT are obstruction, agglutination and the fixation of intestinal loops, mural thickening, ascites, localized fluid collections, peritoneal thickening and enhancement, peritoneal or mural calcifications and reactive adenopathy [Figure 5]. [2],[5]{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}

Differential diagnosis on CT includes congenial peritoneal encapsulation. It is usually asymptomatic, found in older patients and characterized by a thin accessory peritoneal sac surrounding the small bowel behind omentum. Differential diagnoses on Barium examination are adhesions, closed bowel loop, strangulation, hernia, carcinoid tumors, lymphoma, peritoneal carcinomatosis, radiation enteropathy, bezoars and internal hernia. [9]

This condition has a favorable outcome. Release and removal of the membrane and treating the underlying etiology is the treatment of choice.


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