Reactive Nodular Fibrous Pseudotumor of the Omentum: A Rare Case Report and Literature Review

Reactive nodular fibrous pseudotumor (RNFP) is a rare, benign, reactive lesion of the gastrointestinal tract that can clinically and radiologically mimic malignant tumors. It has been associated with prior surgical intervention, trauma, or inflammation. We report a case of RNFP in a patient without any history of abdominal surgery or abdominal discomfort. Imaging findings included multiple, well-defined, solid omental masses that were isodense on CT and hypointense on both T1- and T2-weighted MRI, with progressive, mild contrast enhancement. Ultrasound and contrast-enhanced ultrasound revealed hypoechoic masses with limited contrast uptake. To our knowledge, this is the first reported case in which RNFP was comprehensively evaluated using CT, MRI, ultrasound, and contrast-enhanced ultrasound. Furthermore, it is the first case to specifically distinguish RNFP from Gardner fibroma.