Inflammatory Pseudotumor in the Epidural Space of the Lumbosacral Spine on F-18 FDG PET/CT

An inflammatory pseudotumor (IPT) is a rare benign lesion, characterized by nonneoplastic proliferation of inflammatory cells and presence of intermingling collagen fibers. IPT commonly occurs in the lungs and orbita, while an intraspinal IPT is extremely rare. IPT can mimic both clinically and radiologically malignant processes, and making a definitive preoperative diagnosis is often difficult. Recently, 18-fluorine fluorodeoxyglucose (18F-FDG) has been reported to accumulate in IPT in the lung, spleen, liver, pancreas, colon, orbit, mediastinum, and mesentery. However, to the best of our knowledge, accumulation of 18F-FDG has not been reported in lumbosacral intraspinal IPT. Herein, we report a case of IPT in the epidural space of the lumbar spine, using the imaging findings of 18F-FDG positron emission tomography-computed tomography (PET/CT) and contrastenhanced magnetic resonance imaging (MRI). This is the first case of IPT in the epidural space, depicted by 18F-FDG PET/CT, which revealed a homogeneous, intense 18F-FDG uptake.