Plasmablastic lymphoma clinically presenting in the urinary tract.

Plasmablastic lymphoma is a high-grade B-cell lymphoma that poses major diagnostic problems and carries an extremely poor prognosis. This tumor was first described in the oral cavity of HIV+ patients but has since been identified in other sites and in seronegative patients. We describe 2 cases of plasmablastic lymphoma of the urinary tract that both presented with hydronephrosis. One occurred in an HIV+ patient and harbored a MYC translocation; the other, in an HIV- patient with no translocation detected.