Case of the Month: February, 2011 Page 2

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Diagnosis: Epiploic Appendagitis.

Two axial CT scans of the lower abdomen show the classic findings of an oval, fat-containing mass anterior to the ascending colon with surrounding inflammatory fat stranding.  There is a characteristic dense focus within the fatty mass which may represent a thrombosed vessel or hemorrhage.



  • Acute inflammation or infarction of epiploic appendages
    • Peritoneal outpouchings originating from the serosal surface of colon, containing blood vessels and fat
  • May be caused by venous occlusion
  • Secondary epiploic appendagitis is caused by inflammation of an adjacent structure
  • Occurs most often in men in 4th and 5th decade

Clinical Findings

  • Findings resemble acute diverticulitis or appendicitis
  • Usually left lower quadrant abdominal pain
  • Fever is usually absent or mild , and white blood cell count is usually normal
  • Vigorous exercise and obesity have been postulated as facilitating torsion of the appendage

Imaging Findings

  • On CT:
    • 1.5-3.5 cm fat density lesion with surrounding inflammatory changes
    • Characteristic central high density focus within fat (54%)
      • Probably representing thrombosed blood vessel
    • Occasionally, fat necrosis may lead to calcification of the appendage
  • On ultrasound:
    • Non-compressible echogenic ovoid mass at point of tenderness with hypoechoic ring (swelling of serosa)
  • More common in LLQ with majority (57%) occurring at the rectosigmoid junction
  • Changes resolve within 6 months

Differential Diagnosis

  • Diverticulitis
  • Mesenteric panniculitis
  • Appendicitis
  • Trauma
  • Omental infarction
  • Ulcerative colitis
  • Neoplasm, i.e. liposarcoma


  • Conservative treatment with pain medication
  • Non-surgical


  • Rare but include adhesions, obstruction, peritonitis, abscess formation


  • Benign and self-limited disease, should result in spontaneous and complete resolution within one week.


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