The clinical challenge of relapsed diffuse large B-cell lymphoma with disseminated infection.

Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is an essential tool in the diagnosis, staging, and assessment of treatment response in the management of lymphoma. Diffuse large B-cell lymphoma (DLBCL) represents the most common type of non-Hodgkin lymphoma (NHL). Although the curability rate is high, there are around 40% of patients exhibit relapse and present a therapeutic challenge. As important as 18F-FDG PET/CT is in the management of DLBCL, there are several limitations and potential pitfalls in assessing treatment response or relapse in patients who are also affected by active infectious disease concurrently. Hence, the knowledge of variable physiologic and altered physiologic uptake is of incredible essence when it comes to interpreting a complex scan. In this case report, we present a patient with relapsed DLBCL complicated by disseminated infection.