Sclerosing encapsulating peritonitis

Contributors: Cafer Zorkun M.D., PhD.

Synonyms and Related Keywords: Abdominal cocoon, sclerosing peritonitis, encapsulating peritonitis, peritonitis chronica fibrosa incapsulata.

Overview
Sclerosing encapsulating peritonitis (SEP) is a rare benign cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.

Etiology

 * Sclerosing encapsulating peritonitis can be idiopathic or mainly secondary to chronic ambulatory peritoneal dialysis, peritoneovenous or ventriculoperitoneal shunts, or treatment with practolol.
 * Various abdominal disorders such as tuberculosis, sarcoidosis, familial mediterranean fever, gastrointestinal malignancy, protein S deficiency, liver transplantation, fibrogenic foreign material and luteinized ovarian thecomas are the other rare causative factors.

Differential Diagnosis
Sclerosing encapsulating peritonitis may be confused with congenital peritoneal encapsulation, which is characterized by a thin accessory peritoneal sac surrounding the small bowel. This asymptomtic condition is generally found incidentally during unrelated surgery and does not fit with the clinical or imaging findings in this group of patients.

Diagnosis

 * Radiographs of the abdomen can show air-fluid levels similar to those in patients with any other cause of small-bowel obstruction.
 * In the appropriate clinical setting, recognition of the entire dilated small bowel at the center of the abdomen and encased within a thick fibrocollageneous membrane, as though it were in a cocoon, on a CT image is diagnostic of sclerosing encapsulating peritonitis.
 * The other imaging findings may include signs of obstruction, fixation of intestinal loops, ascites or localized fluid collections, bowel wall thickening, peritoneal or mural calcification, and reactive adenopathy.

Diagnostic Findings
'''Patient #1:

CT and gross pathological images demonstrate sclerosing encapsulating peritonitis. The patient was on long term peritoneal dialysis'''

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