Hypothermia, Hallucinations, and Atrial Fibrillation Secondary to Diffuse Large B-cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL) in adults, constituting a significant portion of global incidence rates. DLBCL can be further classified via genetic expression profiling into molecular subsets consisting of not-otherwise specified (NOS) subset being the most prevalent, germinal center B-cell-like (GCB) subset, and activated B-cell-like (ABC) subset. The ABC subset, marked by abnormal NF-κB signaling, is associated with poorer outcomes. This report presents an unusual case of a 30-year-old male with no past medical history who was found to have advanced-stage ABC-type DLBCL-NOS, featuring rare symptoms such as hypothermia, autonomic dysfunction, and atrial fibrillation, illustrating the unpredictable clinical manifestations of this aggressive lymphoma and the importance of molecular subtyping in treatment and prognosis.