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CASE REPORT Table of Contents  
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Primary sclerosing encapsulating peritonitis

1 Department of Pathology, Moti Lal Nehru Medical College, Prayagraj, Uttar Pradesh, India
2 Department of Surgery, Moti Lal Nehru Medical College, Prayagraj, Uttar Pradesh, India

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Date of Submission19-Dec-2021
Date of Decision20-Feb-2022
Date of Acceptance29-Apr-2022
Date of Web Publication27-Jan-2023


Sclerosing encapsulating peritonitis also known as cocoon abdomen is a rare chronic inflammatory condition of the peritoneum in which the bowel loops are encircled by a membrane (cocoon formation) within the peritoneal cavity leading to intestinal obstruction. It can be primary (idiopathic) or secondary (chemotherapy, beta-blockers, peritoneal dialysis, shunts, tuberculosis, systemic lupus erythematosus, etc.). The symptomatology report includes recurrent episodes of abdominal pain and vomiting. We present here a case of a 32-year-old male who presented with complaints of being unable to pass stools, vomiting (3–4 times), and abdomen pain for 4 days. This case is considered worth mentioning due to its rarity, lack of identification of secondary causes, and diminutive mention of histopathological aspect.

Keywords: Bowel perforation, cocoon abdomen, peritonitis, small bowel obstruction

How to cite this URL:
Mishra S, Chaudhary K, Tyagi S, Mishra P, Misra V. Primary sclerosing encapsulating peritonitis. Indian J Pathol Microbiol [Epub ahead of print] [cited 2023 Mar 27]. Available from:

   Introduction Top

Sclerosing encapsulating peritonitis (SEP), a rare entity commonly referred to as "abdominal cocoon," was originally described in the 1970s (Foo et al.[1]). Abdominal cocoon refers to partial or total encapsulation of abdominal viscera within a dense fibrous membrane. It has been referred to as "peritonitis chronica fibrosa incapsulata" by Owtschinnikow.[2] It is largely reported in females residing in tropical and subtropical regions.[3] Based on etiology, it is classified as primary (idiopathic) and secondary.[4] Substantially it is difficult to diagnose it preoperatively because magnetic resonance imaging and computed tomography (CT) findings are often non-specific.[5]

   Case History Top

A 32-year-old male presented with the complaints of being unable to pass stools, vomiting (3–4 times), and abdomen pain for 4 days. No history of drug intake and any other chronic illness was present. On per abdomen examination showed an absence of bowel sounds. The hematological and biochemical investigations were within normal limits.

The patient had an ultrasound and CT scan reports done at other places. Ultrasonography showed hepatosplenomegaly along with acute small bowel obstruction due to cocoon formation with suspicion of pneumatosis. CT findings revealed features of sclerosing encapsulated peritonitis with high-grade small bowel obstruction and pneumatosis in trapped ileal loops. Gangrene along with mild interbowel adhesions and pelvic-free fluid with peritoneal thickening. Consolidation in lingula and lower lobes was also reported. No plates were available. Exploratory laparotomy with peritoneal lavage was done and resection of the gangrenous small bowel (two and a half feet) was done. Postoperatively the patient was managed with intravenous fluids, antibiotics, analgesics, and steroids. The resected small bowel was received for histopathological examination.

Grossly, the resected small bowel received measured 37 cm in length showing thickened areas with intervening gangrenous areas [Figure 1]a and [Figure 1]c. On exposing the bowel by cutting through the antimesenteric border, the thickened areas showed fatty infiltration which was seen reaching up to the serosa [Figure 1]b along with white fibrous (thread-like) bands in the mucosa [Figure 1]d. The three most prominent thickened areas, measuring 6.5 × 4.5, 5 × 4.5, and 3 × 2 cm, respectively, were seen at a distance of 37, 15, and 2 cm from the proximal resected end. These thickened areas were in continual with a gangrenous segment which measured 8 cm in length with a cut surface displaying necrosed mucosa. No lymph nodes were dissected out from the attached mesenteric fat.
Figure 1: (a) Resected bowel shows three thickened areas (blue arrows) with intervening gangrenous intestine. (b) Thickened areas show diffuse fatty infiltration seen extending to the lower part of mucosa along with fibrofatty bands. (c) Gangrenous intestine showing necrosed mucosa. (d) Variable-sized fibrous bands grossly

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On microscopy, all the layers of the bowel wall were seen. The mucosa showed hyperplasia. Lamina propria showed dense mixed inflammatory infiltrates. The submucosa was edematous and showed fatty infiltration along with numerous dilated and congested blood vessels and lymphatics. In the deeper part, fatty infiltration was seen in the muscularis propria with thickening and hyperplasia of serosa [Figure 2]a and [Figure 2]b. Serosa and submucosa showed hyperplastic fibrous areas which were highlighted by Van Gieson stain [Figure 2]c. The sections from the gangrenous part revealed a denuded mucosal epithelial lining with underlying layers that showed similar morphology of areas of hemorrhage and inflammatory cells.
Figure 2: (a) The mucosa shows hyperplasia. Lamina propria shows dense mixed inflammatory infiltrates. The submucosa is edematous and shows fatty infiltration along with dilated and congested blood vessels and lymphatics [hematoxylin and eosin (H and E 10×)]. (b) The deeper part shows fatty infiltration in the muscularis propria with thickening and hyperplasia of serosa. (H and E 10×). (c) Van Gieson stain showing dense fibrous bands

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Based on gross and microscopy, the diagnosis of primary encapsulating peritonitis was rendered. The patient progressed well and was discharged from the hospital.

   Discussion Top

SEP (cocoon abdomen) is a rare condition. It is mostly observed in young girls of tropical and subtropical countries, chiefly in China, Malaysia, Singapore, Pakistan, India, Nigeria, Kenya, Saudi Arabia, Israel, and South Africa.[1],[2],[3] It was first described by Foo et al.[1] It was initially termed as peritonitis "chronica fibrosa incapsulata," meaning a membrane clasping the intestine.[6] It is classified into primary (idiopathic) and secondary forms. The secondary causes encompass continuous ambulatory peritoneal dialysis, tuberculosis, systemic lupus erythematosus, sarcoidosis, familial Mediterranean fever, gastrointestinal malignancy, protein S deficiency, liver transplantation, fibrogenic foreign material, luteinized ovarian thecomas, the use of povidone-iodine for abdominal washout, placement of LeVeen shunt for refractory ascites and beta-adrenergic blockers (practolol).[4],[5],[7] Clinical presentation myriad ranges from asymptomatic to chronic obstructive symptoms such as nausea, constipation, anorexia, or mild self-resolving abdominal distention to incidental operative finding of acute small bowel obstruction requiring surgical intervention.[6] Most of the cases are diagnosed during laparotomy carried out for intestinal obstruction or during a diagnostic laparoscopy.[8] A case report by Ani et al.[9] mentioned preoperative diagnosis of their case by CT scan like our case. Radiological investigations like CT scan of the pelvis and abdomen and ultrasonography are helpful in identifying SEP.[10] Cocoon abdomen can be confused with congenital peritoneal encapsulation, typified by a thin accessory peritoneal sac seen surrounding the small bowel. It is an incidental finding.[3] Dissection (open or laparoscopic) of fibrotic membrane and adhesiolysis is a medicament usually employed for the abdominal cocoon.[3],[8] Postoperatively, few problems reported were intra-abdominal infections, enterocutaneous fistula, and a perforated bowel.[11] Literatures searched so far have only discussed the surgical and imaging aspect of SEP with minuscule texts related to histopathology.

   Conclusion Top

SEP is a rare clinical condition, often unanticipated in patients with acute intestinal obstruction. Radiological imaging, especially CT scans, plays a considerable role in establishing the diagnosis but often they are camouflaged by inconclusive imaging findings and vague presentations. Mild symptoms can be alleviated by conservative treatment but severe obstructions and recurrences often require meticulous surgical interventions. It should be included among differentials of unexplained malnutrition and abdominal obstruction mainly in patients after organ transplantation. This case was worth mentioning because the histopathological facet is also equally important for the diagnosis of SEP.

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Conflicts of interest

There are no conflicts of interest.

   References Top

Foo KT, Ng KC, Rauff A, Foong WC, Sinniah R. Unusual small intestinal obstruction in adolescent girls: The abdominal cocoon. Br J Surg 1978;65:427-30.  Back to cited text no. 1
Owtschinnikow PJ. Peritonitis chronica fibrosa incapsulata. Arch für Klinische Chirurgie 1907;83:623-34.  Back to cited text no. 2
Sahoo SP, Gangopadhyay AN, Gupta DK, Gopal SC, Sharma SP, Dash RN. Abdominal cocoon in children: A report of four cases. J Pediatr Surg 1996;31:987-8.  Back to cited text no. 3
Stanley MM, Reyes CV, Greenlee HB, Nemchausky B, Reinhardt GF. Peritoneal fibrosis in cirrhotics treated with peritoneovenous shunting for ascites: An autopsy study with clinical correlations. Dig Dis Sci 1996;41:571-7.  Back to cited text no. 4
Hur J, Kim KW, Park MS, Yu JS. Abdominal cocoon: Preoperative diagnostic clues from radiologic imaging with pathologic correlation. Am J Roentgenol 2004;18:639-41.  Back to cited text no. 5
Machado NO. Sclerosing encapsulating peritonitis. Sultan Qaboos Univ Med J 2016;16:142-51.  Back to cited text no. 6
Maguire D, Srinivasan P, O'Grady J, Rela M, Heaton ND. Sclerosing encapsulating peritonitis after orthotopic liver transplantation. Am J Surg 2001;18:151-4.  Back to cited text no. 7
Ertem M, Ozben V, Gok H, Aksu E. An unusual case in surgical emergency: Abdominal cocoon and its laparoscopic management. J Minim Access Surg 2011;7:184-6.  Back to cited text no. 8
Al Ani AH, Al Zayani N, Najmeddine M, Jacob S, Nair S. Idiopathic sclerosing encapsulating peritonitis (abdominal cocoon) in adult male. A case rereport. Int J Sur Case Rep 2014;5:735-8.  Back to cited text no. 9
Lim MC, Chotai NC, Giron DM. Idiopathic sclerosing encapsulating peritonitis: A rare cause of subacute intestinal obstruction. Case Rep Med 2016;8206894. doi: 10.1155/2016/8206894.  Back to cited text no. 10
Tu JF, Huang XF, Zhu GB, Liao Y, Jiang FZ. Comprehensive analysis of 203 cases with abdominal cocoon. Zhonghua Wei Chang Wai Ke Za Zhi 2006;9:133-5.  Back to cited text no. 11

Correspondence Address:
Swati Mishra,
Department of Pathology, M.L.N. Medical College, George Town, Prayagraj - 211 002, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpm.ijpm_1228_21


  [Figure 1], [Figure 2]


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