The Diagnostic Puzzle: Imaging and Pathology Findings

Confirming a diagnosis of Encapsulating Peritoneal Sclerosis (EPS) requires a “puzzle-piece” approach. Because the symptoms of EPS can overlap with many other abdominal conditions, doctors rely on a combination of your medical history and specialized imaging—primarily a CT scan—to reach a clinical diagnosis ^[1][2].

Exploratory surgery or biopsies are generally not routinely required simply to confirm the diagnosis, as operating on an EPS-affected bowel can be hazardous ^[3].

The Role of CT Imaging

The Computed Tomography (CT) scan is the preferred supportive tool for identifying EPS without surgery ^[4]. When a radiologist looks at your scan, they are searching for a specific set of changes that indicate your peritoneal membrane has transformed into a restrictive shell.

Common findings on an EPS-positive CT scan include ^[4][5][6]:

• Peritoneal Thickening and Calcification: The lining of the abdomen appears thicker than normal and may show bright white spots, which are calcifications (calcium deposits).
• Bowel Tethering or “Cocooning”: The most characteristic sign is when loops of the small intestine are bunched together or “tethered” in the center of the abdomen, sometimes encased in a visible membrane.
• Loculated or Septated Ascites: This refers to fluid in the abdomen that is trapped in small pockets (loculated) or divided by thin walls (septated), rather than flowing freely.
• Bowel-Wall Thickening: The walls of the intestines themselves may appear swollen or dilated due to the pressure and inflammation.

Understanding CT Scoring

To help quantify these findings, some centers use a CT scoring system (such as the Vlijm score). This system assigns points based on the severity of the findings listed above ^[7]. However, this score is an optional adjunct, not a universal rule. Doctors use it alongside your symptoms, nutritional status, and bowel function to help guide treatment, rather than relying on the score alone to make decisions ^[5][8].

Ruling Out the “Mimics”

Because EPS is rare, your doctors must rule out other conditions that can look similar on a scan. These “mimics” include:

• Tuberculous Peritonitis: A bacterial infection that can cause a similar “cocooning” effect. Doctors check for this using clinical context, cultures, or specific imaging features, as a single negative test does not always rule it out ^[9][10].
• Peritoneal Carcinomatosis: The spread of cancer to the abdominal lining. This is considered when the clinical history or fluid analysis suggests malignancy ^[11].
• Adhesive Small Bowel Obstruction: Standard scar tissue from previous surgeries. While adhesions usually involve specific “bands” of tissue, they can coexist with EPS and are sometimes difficult to distinguish completely on a scan ^[12].

Pathology: When Tissue is Examined

If you undergo surgery to treat an obstruction, or if tissue was biopsied for another reason, a pathologist will examine it under a microscope. While this provides strong confirmation of EPS, the findings can sometimes be nonspecific and must be interpreted alongside your clinical history ^[2].

Pathology Glossary (What the terms mean) ^[13][14][15]:

• Dense Fibrocollagenous Membrane: A thick layer of tough, scarred tissue.
• Hyalinization: A specific type of “glassy” scarring within the tissue.
• Loss of the Mesothelial Layer: The thin, protective top layer of the peritoneum is missing.
• Fibroblast Proliferation: An overgrowth of the cells that create scar tissue.
• Fibrin Deposition: Evidence of recent or ongoing inflammation and “leaky” blood vessels.
• Vascular Changes: Damage or narrowing of the small blood vessels within the membrane.

A report containing these terms supports the diagnosis of EPS, but you should always ask your specialist to interpret the report rather than trying to self-diagnose ^[10].