Sclerosing mesenteritis

Last revised by Joshua Yap on 30 Sep 2022

Sclerosing mesenteritis, also referred to as mesenteric panniculitis or retractile mesenteritis​, is an uncommon idiopathic disorder characterized by chronic non-specific inflammation involving the adipose tissue of the bowel mesentery. It is often considered in the spectrum of autoimmune disease 21.

Typically this condition afflicts adults in their 60s with a mild male predilection, although reports vary 1,2,4.

Numerous associated conditions have been variably described including 1,4:

There is debate about the association between systemic inflammatory conditions and mesenteric panniculitis. Determining causation is difficult. The term "secondary mesenteric panniculitis" is reserved by some authors for patients with systemic inflammatory conditions. Most authors would not use the term when there is a local cause for mesenteric inflammation.

Clinical presentation can be variable with fever and abdominal pain common 20. Intestinal obstruction or ischemia, a mass, or diarrhea may also be present ref. Altered bowel habits and weight loss may be present in some cases ref. Occasionally, intermittent partial bowel obstruction is encountered 2. A firm left upper quadrant / central abdominal mass may be felt 2. In some situations sclerosing mesenteritis is asymptomatic.

The small bowel mesentery is affected in most cases although the sigmoid mesocolon and omentum can also occasionally be involved. 

The disease is said to pass through three stages, although some authors believe these to be separate entities 4:

  1. mesenteric lipodystrophy: degeneration of mesenteric fat

  2. mesenteric panniculitis: inflammatory reaction

  3. retractile mesenteritis / sclerosing mesenteritis: fibrosis, which may be associated with distortion or lymphatic obstruction

Macroscopically, the mesentery is thickened with either solitary or multiple focal masses 4.

Histology demonstrates 1:

  1. lipid-laden macrophages (mesenteric lipodystrophy)

  2. lymphocytic aggregates and lymphoid follicles (mesenteric panniculitis)

  3. variable amounts of fibrosis (retractile mesenteritis)

Ultrasound typically demonstrates distortion and thickening of the root of the mesentery with a slight increase in echogenicity. Mass effect may be evident 3. A halo of sparing around vessels may be also seen on ultrasound as a region of hypoechoic fat 3. Color Doppler may show non-deviated mesenteric vessels within the mass 17.

CT features are somewhat dependent on the main tissue component and include:

  • well-demarcated or ill-defined mesenteric mass-like lesion with surrounding "misty" attenuation

  • "misty" soft-tissue attenuation

The mesentery demonstrates mass effect and may have a ground glass opacity (misty mesentery). Typically the traversing mesenteric vessels and soft tissue nodules have a spared fat halo (this has sometimes been referred to as the fat ring sign). Its orientation is aligned with the root of the jejunal mesentery. Punctate/coarse calcifications (~20%), as well as small lymph nodes (usually <5 mm), may be present within the region.

The Coulier criteria can be used to diagnose sclerosing mesenteritis on CT 8:

  • sign 1: the presence of well-defined mass effect on neighboring structures 

  • sign 2: constituted by mesenteric fat tissue of inhomogeneous higher attenuation than adjacent retroperitoneal or meso-colonic fat 

  • sign 3: containing small soft tissue nodes 

  • sign 4: may typically be surrounded by a hypo-attenuated fatty "halo sign" 

  • sign 5: hyperattenuating pseudocapsule may also surround the entire entity 

The last two signs are considered inconstant but very specific.

Findings are similar to CT. One report described a fibrous capsule around the inflammation 12.

FDG PET-CT is useful for differentiating between sclerosing mesenteritis and malignant mesenteric involvement.

  • sclerosing mesenteritis (or one of its stages): not FDG-avid

  • malignant mesenteric involvement: FDG-avid

This is especially useful in patients with lymphoma 10. If in doubt, biopsy may be indicated in selected patients, even in asymptomatic lesions 11.

The mainstay of treatment is supportive, as the disease is typically self-limiting. If severe or protracted, medical therapy with corticosteroids, cyclophosphamide or azathioprine can be contemplated 2. Mesenteric panniculitis cannot be completely resected and surgery is of no benefit. In up to 15% of cases, local lymphoma eventually develops 2,4. Some authors suggest an associated malignancy rate of approximately 56% 16.

It was first described by Jura in 1924 as “retractile mesenteritis” and further labeled as “mesenteric panniculitis” by Odgen later in the 1960s.

General imaging differential considerations include:

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Cases and figures

  • Case 1
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  • Case 2
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  • Case 3: ultrasound
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  • Case 4
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  • Case 5
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  • Case 6
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  • Case 7
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  • Case 8
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  • Case 9
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  • Case 10: mesenteric panniculitis
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  • Case 11: mesenteric panniculitis
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  • Case 12: mesenteric panniculitis
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  • Case 13: mesenteric panniculitis
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  • Case 14: sclerosing mesenteritis
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  • Case 15: mesenteric panniculitis
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  • Case 16: mesenteric panniculitis
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