Clinical History:
45-year-old white male admitted to E.R. with 24 hour history of left lower
quadrant pain which was sudden in onset and associated with nausea but no
vomiting. Patient noted no change in bowel habits. Physical exam revealed
focal tenderness in the lateral aspect of the left lower quadrant without
palpable mass or rebound. The patient was afebrile. The total WBC count
was 7.3 with a normal differential (50% neutrophils, 39% lymphocytes).
Radiographic Findings:
Axial CT images reveal a focal, ovoid mass anterior to the descending colon
which is composed of fat with a well demarcated hyperdense rim. There is
infiltration into the surrounding fat without involvement of the adjacent
descending colon wall. A faint central hyperdense area is noted.
Discussion:
The epiploic appendices are pedunculated masses of adipose tissue which
protrude from the serosal surface of the colon. There are 50 ¹ 100 epiploic
appendices present in most individuals, which are oriented in 2 longitudinal
rows along the colon surface extending from the cecum to the rectosigmoid
junction.
Primary epiploic appendagitis is a spontaneous intra-abdominal inflammatory
process due to either torsion and/or thrombosis of one or more of the
epiploic appendages with subsequent ischemia and/or hemorrhagic infarction
and surrounding inflammatory changes. This entity is much more common
than previously believed and is frequently mistaken for diverticulitis
or appendicitis. This disease is characterized by an abrupt onset of focal
abdominal pain similar to that of diverticulitis or appendicitis. The
onset of pain is frequently noted following physical exertion or stretching.
The pain is described as constant and is exacerbated by stretching of
the abdomen, coughing or deep inspiration. Rebound tenderness is noted
in nearly all patients. Physical exam is similar to that of acute diverticulitis,
appendicitis, or other pelvic/abdominal inflammatory process. Fever, nausea,
vomiting, constipation or diarrhea are not prominent features.
The radiographic findings on CT are that of a focal pericolonic, round
to oval-shaped lesion (1-4 cm) with fat attenuation (though higher in
attenuation than the adjacent, uninvolved fat) , hyperdense peripheral
rim, and periappendageal fat stranding. A central high-attenuation "dot"
within the pericolonic lesion is a highly characteristic finding and is
felt to represent the thrombosed vascular pedicle or focal hemorrhagic
necrosis. Bowel wall thickening and ascites are usually not present. US
examination demonstrates an ovoid to round solid, hyperechoic, noncompressible
mass located directly beneath the abdominal wall at the point of maximal
tenderness which is attached to the underlying colon. The masses are frequently
noted to be fixed to the anterior parietal peritoneum. A surrounding hypoechoic
rim corresponds to surrounding inflammation.
This disease is self-limited and resolves with supportive treatment. The
pain usually resolves within 14 days of illness onset.
Diagnosis:
Primary epiploic appendagitis
References:
- Rao PM, Wittenberg J, Lawrason JN. Primary epiploic
appendagitis: evolutionary changes in CT appearance. Radiology. 1997;204:713-717.
- Rioux M, Langis P. Primary epiploic appendagitis: clinical,
US, and CT findings in 14 cases. Radiology. 1994;191:523-526.
- Ghahremani GG, White EM, Hoff FL, Gore RM, Miller
JW, Christ ML. Appendices epiploicae of the colon: radiologic and pathologic
features. RadioGraphics. 1992;12:59-77.
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