ULTRASONOGRAPHIC FINDINGS:
A complex mass in the anterolateral wall of the left lower abdomen quadrant showing an echogenic component resulting from omental eriation in continuity with the abdominal cavity .
On Colour Doppler study , no flow is seen in the mass.
The lesion appears surrounded by a fluid collection.
CT FINDINGS:
Unenhanced and contrast enhanced TC clearly identifies a mass protruding from the abdomen trough a defect in the aponeuorosis of the anterior wall, just distal to the lateral border of the left rectus abdominis muscle.
The hernia sac is “intermuscolar” located deep to external oblique aponeurosis, between external oblique and internal oblique muscles.
The hernia sac contains omentum and fat and showed increased attenuation of the normal fat tissue with fuzzy irregular borders, surrounded by a thin layer of free fluid.
Clinical Cases
PRESENTATION
A 64 years old man with acute abdominal pain and palpable mass in the left lower quadrant
Spigelian hernia is a protrusion of intra-abdominal fat and/or bowel througt a defect in the Spigelian aponeurosis.
In case of omental hernia a rare complication is the omental infarction.
Segmental omental infarctions are rare and can cause acute abdomen.
The pathophysiology of omental infarction is similar to that of epiploic appendagitis: torsion or spontaneous venous thrombosis.Primary torsion has no known cause. Secondary torsion is more common, and the causes include a hernia, a focus of inflammation, previous laparotomy, or a tumor.
Omental infarction and epiploic appendagitis may have a similar imaging appearance.
Failure to differentiate the two entities is common but not clinically relevant because the treatment of both conditions is conservative.
REFFERENCES
Irma Sanchez Montes, MD, MBA, FACS ,Maximo Deysine, MD, FACS, Spigelian and other uncommon hernia repairs, Surgical Clinics of North America Volume 83 • Number 5 • October 2003
Eunhye Yoo, MD, Joo Hee Kim, MD, Myeong-Jin Kim, MD, Jeong-Sik Yu, MD, Jae-Joon Chung, MD, Hyung-Sik Yoo, MD, and Ki Whang Kim, MD ; Greater and Lesser Omenta: Normal Anatomy and Pathologic Processes ; RadioGraphics 2007;27:707-720
Van Breda Vriesman AC, Lohle PN, Coerkamp EG, Puylaert JB. Infarction of omentum and epiploic appendage: diagnosis, epidemiology and natural history. Eur Radiol 1999; 9:1886-1892
Jose M. Pereira, MD, Claude B. Sirlin, MD, Pedro S. Pinto, MD and Giovanna Casola, MD;CT and MR Imaging of Extrahepatic Fatty Masses of the Abdomen and Pelvis: Techniques, Diagnosis, Differential Diagnosis, and Pitfalls : RadioGraphics 2005;25:69-85
Omental infarct through a Spigelian hernia
Autore: Dr Gildo Matta;
Dr.Danilo Sirigu;
Servizio di Radiologia, Azienda Ospedaliera Brotzu, Cagliari
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