Plasmablastic lymphoma, light micrograph. Plasmablastic lymphoma is a variant of diffuse large B-cell lymphoma seen mainly in immunodeficient patients (those with HIV, autoimmune diseases or organ transplant recipients). Occasional cases occur in immunocompetent individuals. The most common location is the oral cavity. There is striking male predominance and the median age is 4th and 5th decades of life. The prognosis is poor; majority of the patients die within one year of diagnosis. The tumour is composed of diffuse sheets of large plasmablasts with eccentric nuclei, single central prominent nucleolus, and abundant basophilic cytoplasm. Mitotic activity and apoptosis are prominent.