A rare aggressive B-cell non-Hodgkin lymphoma characterized by neoplastic cells resembling B immunoblasts or plasmablasts with a CD20-negative plasmacytic phenotype. The tumor may occur in the oral cavity, the gastrointestinal tract, or other, predominantly extranodal, sites and is typically associated with immunodeficiency or -suppression. The tumor cells are EBV-positive in most cases. Patients often present with disseminated bone involvement. Paraproteinemia may also be detected. Prognosis is generally poor. [from
ORDO]