This lecture provides an overview of the heterogeneous spectrum of lymphoproliferative disorders that arise in various immunodeficiency settings. These disorders are variably associated with viruses such as EBV and HHV8 and may show overlapping features in clinically diverse settings. Recognition of an underlying immunodeficiency is important because it impacts treatment decisions. There is benefit in adopting a common framework and vocabulary across categories to better gain biological insights and guide clinical management.