Appendicitis epiploica

Appendicitis
epiploica am Colon descendens: Typische ringförmige Striktur mit zentralen fettdichten Werten und Umgebungsinjektion. Differenzialdiagnostisch ist eine fokale Infarzierung oder Infektion des Omentum majus bei dem gefäßgesunden jungen Mann deutlich unwahrscheinlicher.
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Primary
epiploic appendagitis: a rare cause of acute abdomen. Abdomino-pelvic showed a fat-density ovoid structure adjacent to sigmoid, the centre of which was slightly hyperdense, with thin high-density rim, and surrounding inflammatory fat stranding. Mild thickening of adjacent visceral peritoneum was also noted.
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Epiploic
appendagitis • Synchronous acute appendicitis and epiploic appendagitis of the appendix - Ganzer Fall bei Radiopaedia
Pfleger, R. Synchronous acute appendicitis and epiploic appendagitis of the appendix. Case study, Radiopaedia.org. (accessed on 31 Oct 2022) https://doi.org/10.53347/rID-40922 • CC by-nc-sa 3.0 (modified)
Primary
epiploic appendagitis: a rare cause of acute abdomen. Abdomino-pelvic showed a fat-density ovoid structure adjacent to sigmoid, the centre of which was slightly hyperdense, with thin high-density rim, and surrounding inflammatory fat stranding. Mild thickening of adjacent visceral peritoneum was also noted.
www.eurorad.org • CC by-nc-sa-4.0
Primary
epiploic appendagitis: a rare cause of acute abdomen. Abdomino-pelvic showed a fat-density ovoid structure adjacent to sigmoid, the centre of which was slightly hyperdense, with thin high-density rim, and surrounding inflammatory fat stranding. Mild thickening of adjacent visceral peritoneum was also noted.
www.eurorad.org • CC by-nc-sa-4.0
Identification
of the cause of abdominal pain on CT in a patient with multiple incidental findings. Well defined small fat-density ovoid structure with thin high-density rim and perilesional minimal inflammatory fat stranding.
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Appendicitis
epiploica in der Sonographie. Operativ bestätigt: Torsion der Appendix epiploica.
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Epiploic
appendagitis in computertomography sagittal view.
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Epiploic
appendagitis in computertomography coronal view.
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Epiploic
appendagitis in computertomography sagittal view.
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Epiploic
appendagitis in computertomography coronal view.
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Appendicitis
epiploica in der Computertomographie: Das umgebende Fett ist entzündlich verdichtet.
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Identification
of the cause of abdominal pain on CT in a patient with multiple incidental findings. Well defined echogenic lesion with peripheral hypoechoic rim seen in left iliac fossa.
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Identification
of the cause of abdominal pain on CT in a patient with multiple incidental findings. Well defined echogenic lesion with hypoechoic rim and with minimal perilesional fluid in left iliac fossa.
www.eurorad.org • CC by-nc-sa-4.0
Identification
of the cause of abdominal pain on CT in a patient with multiple incidental findings. Well defined small fat-density ovoid structure just anterior to descending colon with thin high-density rim and perilesional minimal inflammatory fat stranding.
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Epiploic
appendagitis in computertomography.
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School ager
with right lower quadrant pain. Coronal (above left and above middle) and sagittal (above right) CT with contrast of the abdomen shows a fat-density ovoid lesion adjacent to the ascending colon with a thin high-density rim and surrounding inflammatory fat stranding and mild colonic wall thickening. The axial CT (below) shows the lesion to have a central hyperdense dot. The diagnosis was epiploic appendagitis.
pediatricimaging.org • CC-by-nc-sa 4.0
Epiploic
appendagitis in computertomography.
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Radiopaedia • CC-by-nc-sa 3.0 • de

Epiploic appendagitis is a rare self-limiting ischemic/inflammatory process involving appendix epiploica of the colon and may either be primary or secondary to adjacent pathology. This article pertains to primary (spontaneous) epiploic appendagitis. The term along with omental infarction is grouped under the broader umbrella term intraperitoneal focal fat infarction .

Epidemiology

This condition usually affects patients in their 2 to 5decades with a predilection for women and obese individuals, presumably due to larger appendages .

Clinical presentation

Clinically, patients present with abdominal pain and guarding. It is essentially indistinguishable from diverticulitis and acute appendicitis (depending on location) and, although an uncommon condition, it accounts for up to 7% of cases of suspected diverticulitis . Since there is focal peritoneal irritation, pain may be more localized than with other causes of acute abdominal pain.

Pathology

Epiploic appendagitis merely denotes inflammation of the one or more appendices epiploicae, which number 50-100 and are distributed along with the large bowel with variable frequency :

  • rectosigmoid junction: 57%
  • ileocecal region: 26%
  • ascending colon: 9%
  • transverse colon: 6%
  • descending colon: 2%

The pathogenesis is thought to be due to torsion of a large and pedunculated appendage epiploicae, or spontaneous thrombosis of the venous outflow, resulting in ischemia and necrosis .

Radiographic features

Ultrasound

Ultrasound evaluation of the patient's area of maximal tenderness may reveal a rounded, non-compressible, hyperechoic mass, without internal vascularity, and surrounded by a subtle hypoechoic line . They are typically 2-4 cm in maximal diameter.

They typically exert local mass effect but are not usually associated with bowel wall thickening or ascites .

CT

The CT appearance is usually characteristic:

  • a fat-density ovoid structure adjacent to the colon, usually 1.5-3.5 cm in diameter
  • thin high-density rim, known as the hyperattenuating ring sign (1-3 mm thick)
  • surrounding inflammatory fat stranding, and thickening of the adjacent peritoneum
  • a central hyperdense dot (representing the thrombosed vascular pedicle)
  • adjacent colonic wall thickening is not usually associated, but if present is usually minimal and the amount of fat inflammation is out of proportional to colonic wall thickening
  • the inflamed appendage is classically located on the anterior aspect of the sigmoid or descending colon, but it may be located anywhere along the circumference of the colon, as seen in the atypical Case 22.

Chronically, an infarcted epiploic appendage may calcify and may detach to form an intraperitoneal loose body (peritoneal 'mice').

It may rarely involve the vermiform appendix epiploic appendages as so-called "epiploic appendagitis of the vermiform appendix" , mimicking appendicitis both clinically and potentially on CT.

MRI

Although uncommonly used in a setting of acute abdominal pain, MRI features are also characteristic :

  • T1: often shows a rounded high signal mass with slightly reduced signal compared to normal fat, due to inflammatory stranding; hypointense 2-3 mm rim
  • T2: often seen as a high signal mass which attenuates on fat-suppressed sequences; hyperintense 2-3 mm rim with surrounding high signal stranding; central low signal vein
  • T1 C+ (Gd): shows vivid rim enhancement

Treatment and prognosis

Epiploic appendagitis is a self-limiting disease, and thus correct identification on CT prevents unnecessary surgery . Although it sometimes mimics acute abdominal diseases for which surgery is required, treatment options for epiploic appendagitis often do not include surgery; it usually responds well to NSAIDs.

Differential diagnosis

Imaging differential considerations include:

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Appendicitis epiploica:
Divertikulitis
 
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Appendizitis
 
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