DOI: 10.1148/rg.256055030
Acute Epiploic Appendagitis and Its Mimics1
Ajay K. Singh, MD,
Debra A. Gervais, MD,
Peter F. Hahn, MD, PhD,
Pallavi Sagar, MD,
Peter R. Mueller, MD and
Robert A. Novelline, MD
1 From the Department of Radiology, University of Massachusetts Medical Center, Worcester, MA 01605 (A.K.S.); and the Division of Abdominal Imaging and Interventional Radiology (D.A.G., P.F.H., P.S., P.R.M.) and Department of Emergency Radiology (R.A.N.), Massachusetts General Hospital, Boston, Mass. Recipient of a Certificate of Merit award for an education exhibit at the 2004 RSNA Annual Meeting. Received February 25, 2005; revision requested March 22 and received May 2; accepted May 3. All authors have no financial relationships to disclose.
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Figure 1a. Normal epiploic appendages. Axial source image (a) and coronal reconstruction (b) obtained with contrast material–enhanced CT show multiple appendices epiploicae (oval line) that arise from the sigmoid colon and are outlined by a hyperattenuating rim due to ascites.
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Figure 1b. Normal epiploic appendages. Axial source image (a) and coronal reconstruction (b) obtained with contrast material–enhanced CT show multiple appendices epiploicae (oval line) that arise from the sigmoid colon and are outlined by a hyperattenuating rim due to ascites.
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Figure 2a. Acute epiploic appendagitis near the sigmoid colon. Axial contrast-enhanced CT images (a in a different patient than b) show inflamed epiploic appendages (arrow) that have a hyperattenuating rim and that abut the sigmoid colon.
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Figure 2b. Acute epiploic appendagitis near the sigmoid colon. Axial contrast-enhanced CT images (a in a different patient than b) show inflamed epiploic appendages (arrow) that have a hyperattenuating rim and that abut the sigmoid colon.
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Figure 3a. Acute epiploic appendagitis with a hyperattenuating center. Axial contrast-enhanced CT images (a in a different patient than b) show a lesion (arrow) that abuts the sigmoid colon and has a central focal area of hyperattenuation with surrounding inflammation.
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Figure 3b. Acute epiploic appendagitis with a hyperattenuating center. Axial contrast-enhanced CT images (a in a different patient than b) show a lesion (arrow) that abuts the sigmoid colon and has a central focal area of hyperattenuation with surrounding inflammation.
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Figure 4a. Acute epiploic appendagitis near the cecum. Axial contrast-enhanced CT images (a in a different patient than b) show lesions (arrow) with fat attenuation and surrounding inflammation that abut the cecum. (Fig 4b reprinted, with permission, from reference 5.)
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Figure 4b. Acute epiploic appendagitis near the cecum. Axial contrast-enhanced CT images (a in a different patient than b) show lesions (arrow) with fat attenuation and surrounding inflammation that abut the cecum. (Fig 4b reprinted, with permission, from reference 5.)
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Figure 5a. Acute epiploic appendagitis near the descending colon. Axial contrast-enhanced CT images (a in a different patient than b) show an epiploic appendage (arrow), anterior to the descending colon, that is surrounded by inflammation but that has no hyperattenuating center.
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Figure 5b. Acute epiploic appendagitis near the descending colon. Axial contrast-enhanced CT images (a in a different patient than b) show an epiploic appendage (arrow), anterior to the descending colon, that is surrounded by inflammation but that has no hyperattenuating center.
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Figure 6. Acute epiploic appendagitis in a hernia sac. Axial contrast-enhanced CT image shows an inflamed appendix epiploica (arrow) that arose from the transverse colon in a patient with a ventral hernia that developed after gastric bypass surgery. (Reprinted, with permission, from reference 21.)
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Figure 7a. Evolutionary changes in acute epiploic appendagitis. (a) Axial contrast-enhanced CT image acquired on the day of presentation shows a lesion with fat attenuation, a typical finding in acute epiploic appendagitis. (b) Axial contrast-enhanced CT image obtained 3 months later shows a small residual nodule with soft-tissue attenuation (arrow). (c) Axial contrast-enhanced CT image obtained in another patient at presentation shows an inflamed appendix epiploica with a hyperattenuating rim (arrow). (d) Axial contrast-enhanced CT image obtained 3 months later shows a decrease in size of the inflamed appendix epiploica (arrow), which has a fatty center and abuts the sigmoid colon.
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Figure 7b. Evolutionary changes in acute epiploic appendagitis. (a) Axial contrast-enhanced CT image acquired on the day of presentation shows a lesion with fat attenuation, a typical finding in acute epiploic appendagitis. (b) Axial contrast-enhanced CT image obtained 3 months later shows a small residual nodule with soft-tissue attenuation (arrow). (c) Axial contrast-enhanced CT image obtained in another patient at presentation shows an inflamed appendix epiploica with a hyperattenuating rim (arrow). (d) Axial contrast-enhanced CT image obtained 3 months later shows a decrease in size of the inflamed appendix epiploica (arrow), which has a fatty center and abuts the sigmoid colon.
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Figure 7c. Evolutionary changes in acute epiploic appendagitis. (a) Axial contrast-enhanced CT image acquired on the day of presentation shows a lesion with fat attenuation, a typical finding in acute epiploic appendagitis. (b) Axial contrast-enhanced CT image obtained 3 months later shows a small residual nodule with soft-tissue attenuation (arrow). (c) Axial contrast-enhanced CT image obtained in another patient at presentation shows an inflamed appendix epiploica with a hyperattenuating rim (arrow). (d) Axial contrast-enhanced CT image obtained 3 months later shows a decrease in size of the inflamed appendix epiploica (arrow), which has a fatty center and abuts the sigmoid colon.
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Figure 7d. Evolutionary changes in acute epiploic appendagitis. (a) Axial contrast-enhanced CT image acquired on the day of presentation shows a lesion with fat attenuation, a typical finding in acute epiploic appendagitis. (b) Axial contrast-enhanced CT image obtained 3 months later shows a small residual nodule with soft-tissue attenuation (arrow). (c) Axial contrast-enhanced CT image obtained in another patient at presentation shows an inflamed appendix epiploica with a hyperattenuating rim (arrow). (d) Axial contrast-enhanced CT image obtained 3 months later shows a decrease in size of the inflamed appendix epiploica (arrow), which has a fatty center and abuts the sigmoid colon.
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Figure 8a. Acute epiploic appendagitis in the descending colon in a 34-year-old woman. (a) US image of the left lower quadrant shows an oval noncompressible lesion (arrows) with heterogeneous echotexture, located at the point of maximum tenderness. (b) Axial contrast-enhanced CT image shows the corresponding inflamed appendix epiploica (arrow) anterior to the distal descending colon.
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Figure 8b. Acute epiploic appendagitis in the descending colon in a 34-year-old woman. (a) US image of the left lower quadrant shows an oval noncompressible lesion (arrows) with heterogeneous echotexture, located at the point of maximum tenderness. (b) Axial contrast-enhanced CT image shows the corresponding inflamed appendix epiploica (arrow) anterior to the distal descending colon.
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Figure 9a. Evolutionary changes in omental infarction. (a) Axial contrast-enhanced CT image obtained after colectomy shows an acute omental infarct (arrows) in the left upper quadrant. (b) Axial contrast-enhanced CT image obtained 3 years later shows a small residual lesion (arrow) with the attenuation of fat and with well-defined margins.
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Figure 9b. Evolutionary changes in omental infarction. (a) Axial contrast-enhanced CT image obtained after colectomy shows an acute omental infarct (arrows) in the left upper quadrant. (b) Axial contrast-enhanced CT image obtained 3 years later shows a small residual lesion (arrow) with the attenuation of fat and with well-defined margins.
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Figure 10a. Multiple omental infarcts secondary to superior mesenteric artery obstruction. (a, b) Axial contrast-enhanced CT images (a in a different patient than b) show multiple fatty lesions (straight arrows) in the omentum and ischemic changes (curved arrow) in the small-bowel loops. (c) Sagittal CT angiographic image shows complete occlusion of the superior mesenteric artery 2 cm beyond its origin (arrow). (Reprinted, with permission, from reference 24.)
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Figure 10b. Multiple omental infarcts secondary to superior mesenteric artery obstruction. (a, b) Axial contrast-enhanced CT images (a in a different patient than b) show multiple fatty lesions (straight arrows) in the omentum and ischemic changes (curved arrow) in the small-bowel loops. (c) Sagittal CT angiographic image shows complete occlusion of the superior mesenteric artery 2 cm beyond its origin (arrow). (Reprinted, with permission, from reference 24.)
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Figure 10c. Multiple omental infarcts secondary to superior mesenteric artery obstruction. (a, b) Axial contrast-enhanced CT images (a in a different patient than b) show multiple fatty lesions (straight arrows) in the omentum and ischemic changes (curved arrow) in the small-bowel loops. (c) Sagittal CT angiographic image shows complete occlusion of the superior mesenteric artery 2 cm beyond its origin (arrow). (Reprinted, with permission, from reference 24.)
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Figure 11a. Infected omental infarct. (a) Axial contrast-enhanced CT image obtained after pancreatectomy and splenectomy shows an omental infarct with attenuation of fat and a fluid-filled center that indicates an abscess (arrows). (b) Follow-up CT image obtained after percutaneous catheter drainage shows resolution of the abscess.
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Figure 11b. Infected omental infarct. (a) Axial contrast-enhanced CT image obtained after pancreatectomy and splenectomy shows an omental infarct with attenuation of fat and a fluid-filled center that indicates an abscess (arrows). (b) Follow-up CT image obtained after percutaneous catheter drainage shows resolution of the abscess.
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Figure 12. Acute omental infarction in a young woman. Axial contrast-enhanced CT image shows an oval lesion with heterogeneous attenuation (straight arrows), well separated from the colon (curved arrow), in the right lower quadrant.
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Figure 13. Acute omental infarction in a 6-year-old girl. Axial contrast-enhanced CT image shows a 6.5-cm-diameter fatty mass with surrounding inflammation in the right lower quadrant. Because the mass is large, the diagnosis of omental infarction was favored over that of epiploic appendagitis, in which the lesion is usually less than 5 cm long.
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Figure 14. Acute cecal diverticulitis in a young woman. Axial contrast-enhanced CT image shows a central focal area with low attenuation, which represents an inflamed diverticulum (arrow), surrounded by a rim of higher attenuation due to intense inflammation. An uninflamed diverticulum also is visible posterior to the inflamed diverticulum.
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Figure 15a. Secondary inflammation of epiploic appendages. (a) Axial contrast-enhanced CT image shows thickening of the cecal wall (areas of low attenuation inside the oval line) because of colitis, with secondary inflammation of an epiploic appendage (arrow). (b) In a different patient, axial contrast-enhanced CT image shows acute sigmoid diverticulitis (oval) with inflammation in surrounding tissues, including an epiploic appendage (arrow). (c) In a patient with a pelvic abscess, axial contrast-enhanced pelvic CT image shows areas of inflammation-related high attenuation that outline two epiploic appendages (arrows).
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Figure 15b. Secondary inflammation of epiploic appendages. (a) Axial contrast-enhanced CT image shows thickening of the cecal wall (areas of low attenuation inside the oval line) because of colitis, with secondary inflammation of an epiploic appendage (arrow). (b) In a different patient, axial contrast-enhanced CT image shows acute sigmoid diverticulitis (oval) with inflammation in surrounding tissues, including an epiploic appendage (arrow). (c) In a patient with a pelvic abscess, axial contrast-enhanced pelvic CT image shows areas of inflammation-related high attenuation that outline two epiploic appendages (arrows).
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Figure 15c. Secondary inflammation of epiploic appendages. (a) Axial contrast-enhanced CT image shows thickening of the cecal wall (areas of low attenuation inside the oval line) because of colitis, with secondary inflammation of an epiploic appendage (arrow). (b) In a different patient, axial contrast-enhanced CT image shows acute sigmoid diverticulitis (oval) with inflammation in surrounding tissues, including an epiploic appendage (arrow). (c) In a patient with a pelvic abscess, axial contrast-enhanced pelvic CT image shows areas of inflammation-related high attenuation that outline two epiploic appendages (arrows).
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Figure 16a. Sclerosing mesenteritis. Axial contrast-enhanced CT images show variable degrees of fibrosis, fat necrosis, lymphadenopathy, and inflammation in four patients with sclerosing mesenteritis (arrows). The fat ring sign (arrowheads in a and b) signals the conservation of fat around the superior mesenteric vessels. Because the predominance of soft-tissue attenuation in c and d did not enable differentiation of the findings from malignant neoplasms such as carcinoid and desmoid tumors, a biopsy was performed. Histopathologic analysis demonstrated retractile mesenteritis in the two patients in c and d.
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Figure 16b. Sclerosing mesenteritis. Axial contrast-enhanced CT images show variable degrees of fibrosis, fat necrosis, lymphadenopathy, and inflammation in four patients with sclerosing mesenteritis (arrows). The fat ring sign (arrowheads in a and b) signals the conservation of fat around the superior mesenteric vessels. Because the predominance of soft-tissue attenuation in c and d did not enable differentiation of the findings from malignant neoplasms such as carcinoid and desmoid tumors, a biopsy was performed. Histopathologic analysis demonstrated retractile mesenteritis in the two patients in c and d.
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Figure 16c. Sclerosing mesenteritis. Axial contrast-enhanced CT images show variable degrees of fibrosis, fat necrosis, lymphadenopathy, and inflammation in four patients with sclerosing mesenteritis (arrows). The fat ring sign (arrowheads in a and b) signals the conservation of fat around the superior mesenteric vessels. Because the predominance of soft-tissue attenuation in c and d did not enable differentiation of the findings from malignant neoplasms such as carcinoid and desmoid tumors, a biopsy was performed. Histopathologic analysis demonstrated retractile mesenteritis in the two patients in c and d.
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Figure 16d. Sclerosing mesenteritis. Axial contrast-enhanced CT images show variable degrees of fibrosis, fat necrosis, lymphadenopathy, and inflammation in four patients with sclerosing mesenteritis (arrows). The fat ring sign (arrowheads in a and b) signals the conservation of fat around the superior mesenteric vessels. Because the predominance of soft-tissue attenuation in c and d did not enable differentiation of the findings from malignant neoplasms such as carcinoid and desmoid tumors, a biopsy was performed. Histopathologic analysis demonstrated retractile mesenteritis in the two patients in c and d.
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Figure 17a. Fatty neoplasms in four patients. (a) Well-differentiated liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation fatty mass (straight arrows) that abuts the gallbladder (curved arrow). (b) Postoperative recurrence of liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation retroperitoneal liposarcoma (arrows) that abuts the cecum. (c) Tuberous sclerosis with angiomyolipoma. Axial contrast-enhanced CT image shows exophytic angiomyolipoma (straight arrows) that arises from the lower pole of the right kidney (curved arrow) and abuts the hepatic flexure of the colon. (d) Postoperative recurrence of cecal carcinoma. Axial contrast-enhanced CT image shows fat strands (arrows) lateral to the ileocolonic anastomosis site, which is marked by a bowel suture.
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Figure 17b. Fatty neoplasms in four patients. (a) Well-differentiated liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation fatty mass (straight arrows) that abuts the gallbladder (curved arrow). (b) Postoperative recurrence of liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation retroperitoneal liposarcoma (arrows) that abuts the cecum. (c) Tuberous sclerosis with angiomyolipoma. Axial contrast-enhanced CT image shows exophytic angiomyolipoma (straight arrows) that arises from the lower pole of the right kidney (curved arrow) and abuts the hepatic flexure of the colon. (d) Postoperative recurrence of cecal carcinoma. Axial contrast-enhanced CT image shows fat strands (arrows) lateral to the ileocolonic anastomosis site, which is marked by a bowel suture.
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Figure 17c. Fatty neoplasms in four patients. (a) Well-differentiated liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation fatty mass (straight arrows) that abuts the gallbladder (curved arrow). (b) Postoperative recurrence of liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation retroperitoneal liposarcoma (arrows) that abuts the cecum. (c) Tuberous sclerosis with angiomyolipoma. Axial contrast-enhanced CT image shows exophytic angiomyolipoma (straight arrows) that arises from the lower pole of the right kidney (curved arrow) and abuts the hepatic flexure of the colon. (d) Postoperative recurrence of cecal carcinoma. Axial contrast-enhanced CT image shows fat strands (arrows) lateral to the ileocolonic anastomosis site, which is marked by a bowel suture.
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Figure 17d. Fatty neoplasms in four patients. (a) Well-differentiated liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation fatty mass (straight arrows) that abuts the gallbladder (curved arrow). (b) Postoperative recurrence of liposarcoma. Axial contrast-enhanced CT image shows a mixed-attenuation retroperitoneal liposarcoma (arrows) that abuts the cecum. (c) Tuberous sclerosis with angiomyolipoma. Axial contrast-enhanced CT image shows exophytic angiomyolipoma (straight arrows) that arises from the lower pole of the right kidney (curved arrow) and abuts the hepatic flexure of the colon. (d) Postoperative recurrence of cecal carcinoma. Axial contrast-enhanced CT image shows fat strands (arrows) lateral to the ileocolonic anastomosis site, which is marked by a bowel suture.
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Copyright © 2005 by the Radiological Society of North America.
