EP 181 The Overlooked Omentum: Two Cases of Missed Omental Pathology Mimicking Right Iliac Fossa Malignancy
Altaf Haji, Zain Khan, Kalimuthu Marimuthu, Lina Moawad, Ratandeep Ganguly, Suki BernsteinAbstract
Keywords
Omentum, Right Iliac Fossa, Florid Mesothelial Proliferation, Actinomycosis, Diagnostic Error, Radiology, MDT
Right iliac fossa (RIF) pain is a common surgical presentation, often attributed to appendicitis or gynaecological disease. However, omental pathology may rarely mimic malignancy, leading to diagnostic uncertainty and intraoperative surprises. We present two instructive cases where omental lesions, retrospectively visible on CT, were initially missed—emphasising the clinical impact of overlooked imaging findings.
Case 1
A 36-year-old IUCD user presented with suspected caecal malignancy. Laparotomy revealed dense omental adhesions to the caecum and pelvic wall. Histopathology confirmed actinomycosis with sulfur granules and filamentous bacteria. Retrospective CT review again demonstrated unreported omental thickening /Mass.
Case 2
A 64-year-old woman presented with RIF pain. CT suggested appendicitis, but laparoscopy revealed an inflamed appendix and an omental mass adherent to the abdominal wall. Histology confirmed eosinophilic appendicitis with florid mesothelial proliferation. Retrospective CT review identified an unreported ovoid omental lesion, later confirmed benign at multidisciplinary team (MDT) discussion.
These cases highlight that omental pathology, though rare, can mimic intra-abdominal malignancy both clinically and radiologically. Missed omental lesions may alter surgical decision-making and lead to overtreatment. Florid mesothelial proliferation can resemble mesothelioma histologically, while actinomycosis, often linked to IUCD use, is a curable infection when recognised.
A structured radiological review, intraoperative vigilance, and MDT correlation are essential for accurate diagnosis. Greater awareness of omental pathology within surgical and radiology teams can prevent misdiagnosis, improve patient outcomes, and enhance learning from rare but significant diagnostic pitfalls.