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

An inflammatory pseudotumor (IPT) is a rare benign lesion, characterized by non-neoplastic 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 ((18)F-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 (18)F-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 (18)F-FDG positron emission tomography-computed tomography (PET/CT) and contrast-enhanced magnetic resonance imaging (MRI). This is the first case of IPT in the epidural space, depicted by (18)F-FDG PET/CT, which revealed a homogeneous, intense (18)F-FDG uptake.