Intravascular large B-cell lymphoma: The Great Imitator.

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of diffuse large B-cell lymphoma with an estimated incidence of less than one per million. Unlike other hematopoietic malignancies, lymphadenopathy and hepatosplenomegaly are uncommon, and patients typically present with nonspecific symptoms. IVLBCL presents a diagnostic challenge and patients are usually diagnosed late in the disease course, if at all, and the prognosis is poor. The differential diagnosis is broad, and physicians often pursue multiple diagnostic possibilities during patient workup. We present a case of IVLBCL discovered at autopsy in an 80-year-old male who presented with history and symptoms pointing to the tick-borne illness ehrlichiosis.