Currently, CT scan has become the mainstay for diagnosis of EPS. Routine portal venous phase CT scan after intravenous administration of contrast material is sufficient to give adequate information, however administration of positive oral contrast material helps in better bowel delineation.

We have discussed the CT findings in three cases of abdominal cocoon occurring secondary to tuberculosis.

Characteristic CT findings in all our cases consisted of clumped up small bowel loops in the center of the abdomen which was encased by a mantle/fibrocollagenous membrane of soft-tissue attenuation. The length of clumped up small bowel loops ranged from few loops to almost entire small bowel encasement.

Fig. 1: Extent of involvement in abdominal cocoon: (A) Few clumped up small bowel loops in right iliac fossa. (B) Almost entire small bowel loops are clumped up within the membranous sac. (C) Entire small bowel loops with part of transverse colon is seen clumped up within the thick membranous sac.

After intravenous contrast administration, the fibrocollagenous membrane encasing the bowel loops showed heterogeneous enhancement.

Fig. 2: Post contrast axial and coronal images: (A,B) Heterogeneous enhancement of the thick membrane encasing the bowel loops in a male patient. (C,D) Another patient shows mild enhancement of the thin membrane surrounding the clumped up small bowel loops.

In addition to the altered position and placement of the bowel in the abdomen, CT also depicted changes in the contour and caliber of the bowel. Patient with acute presentation showed dilated small bowel loops with multiple air-fluid levels suggesting bowel obstruction. However patient with chronic presentation showed clumped up loops with no air fluid levels.

Fig. 3: Presentation of abdominal cocoon: (A) Acute presentation: Patient shows mildly dilated, clumped up bowel loops with multiple air fluid levels within suggestive of small bowel obstruction. (B) Chronic presentation: Patient shows just clumping of small bowel loops, without air fluid levels within.

Other findings observed included ascites or loculated fluid collections, peritoneal and omental thickening, lymphadenopathy and peritoneal calcifications.

Fig. 4: Secondary findings of abdominal cocoon. (A) Omental thickening (B) Peritoneal thickening (C) Ascites (D) Lymphadenopathy

CT is thus the modality of choice for detecting this condition, delineating the extent and identifying the associated complications.