Encapsulating peritoneal sclerosis

We will discuss a case of encapsulating peritoneal sclerosis, including imaging findings with differential diagnosis. 

28-year-old man presented with pain abdomen associated with vomiting for 1 month. He is having abdominal distension with non passage of faeces and flatus for 1 week. On clinical examination, the abdomen was distended with soft non tender mass palpable in central part of the abdomen. 

X-ray abdomen erect supine was done which shows (a) essentially a normal study. 

USG abdomen was performed which shows (b) central clumping of small bowel loops with a narrow base resembling a cauliflower and shows the characteristic US trilaminar appearance: from superficial to deep formed by a (1) superficial hyperechoic membrane, (2) middle hypoechoic layer of the bowel wall, and a (3) deep hyperechoic layer of bowel gas and/or bowel contents. (c) US image shows septated ascites. 

Subsequently, CECT abdomen was performed which shows (d) clumping of small bowel loops including jejunum and ileal loops in central abdomen which appears mildly prominent and shows enhancing circumferential wall thickening. The clumped bowel loops are encapsulated by a thick enhancing membrane. The sac contains free fluid. There is associated smooth enhancing peritoneal thickening, mesenteric fat heterogeneity and omental nodularity. There is kinking of proximal jejunum at the junction with membrane with resultant upstream dilatation of duodenum measuring 3.5mm in maximal calibre s/o obstruction (e). Mild ascites and bilateral pleural effusion were also present. 

In view of patient history and imaging findings a diagnosis of encapsulating peritoneal sclerosis (EPS) with small bowel obstruction likely secondary to tuberculosis was given. 

EPS is characterised by fibrocollagenous cocoon like encapsulation of the bowel. Causes of this condition are divided into primary (idiopathic) and secondary causes. Secondary causes include peritoneal dialysis, ventriculoperitoneal shunt, tuberculosis, drugs such as beta blockers & methotrexate, autoimmune diseases such as sarcoidosis, SLE and GI malignancies. 

Clinically the patient can present with features of intestinal obstruction with or without a palpable abdominal mass. 

The imaging differential includes:

1)  Congenital peritoneal encapsulation (CEP): it is a benign condition characterised by a thin membrane around small bowel and is usually asymptomatic.

2)   Peritoneal carcinomatosis: it is characterised by nodular peritoneal thickening with nodular deposits in omentum, pouch of Douglas and surface of bowel. 

3)   Internal hernias: they occur in fixed anatomic locations and complication such as bowel ischemia are more common in them.