Ileal inflammatory pseudotumor in adolescent male patient with prior Burkitt lymphoma: A challenging diagnosis.

Inflammatory pseudotumor is a rare benign mesenchymal pediatric neoplasm, that can mimic tumoral residue or relapse at metabolic imaging with nonspecific clinical presentation and difficult diagnosis. We present the case of a 14year old male patient with fever of unknown origin and large ileal mass, diagnosed with and treated for Burkitt lymphoma, who performed several 18-fluoro-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) scans, during and after first line chemotherapy, showing persistent and focal uptake, while ileal mass volume decreased dramatically and the patient was clinically asymptomatic. Histopathological analysis of residual ileal mass was suggestive for xanthomatous pseudotumor, a type of inflammatory pseudotumor. No more treatment was performed and a short-term follow up with 18F-FDG PET/CT showed tracer uptake intensity decreasing progressively over the next few months. This case reports an uncommon presentation of a rare disease, inflammatory pseudotumor of the small bowel developed at the site of treated Burkitt lymphoma, underscoring the potential role of 18F-FDG PET/CT imaging in the diagnosis and management of these rare neoplasms, particularly in asymptomatic patients.