Intravascular Large B-cell Lymphoma Presenting as Sudden Death

Intravascular large B-cell lymphoma is a rare subset of non-Hodgkin lymphoma composed of mature B lymphoma cells confined to the intravascular space. This disease remains elusive because it lacks a discrete tumor mass, can affect any part of the body, and has vague symptoms paired with heterogeneous clinical findings resulting in delayed or missed accurate diagnosis, even at postmortem examination. This is a case of a woman who died within hours of presenting to the emergency department with a diagnosis of intravascular large B-cell lymphoma made through autopsy examination, adding to the knowledge of this rare disease and bringing it to the attention of practicing autopsy and forensic pathologists.