<unk>  was originally thought to be a premalignant condition, termed<unk>  lymphadenopathy, and this atypical reactive lymphadenopathy carried a risk for transformation into a lymphoma. It is postulated that the originating cell for<unk>  is a mature (post-thymic) CD4+ T-cell that arises de novo, or that the disease has a premalignant subtype. The Epstein–Barr virus (EBV) is observed in the majority of cases, being identified in the reactive (i.e. non-malignant) B-cells that comprise part of the polymorphous infiltrate of<unk> . These EBV+ B cells have numerous non-malignant crippling mutations, often proliferate excessively, and in some cases may transform into EBV+ B cell lymphomas. The other cell types in these infiltrates, including the malignant TFH cells, are EBV negative. While the World Health Organization (2016) has classified these EBV-associated cases as one of the Epstein-Barr virus-associated lymphoproliferative diseases (see EBV+<unk> , the role of the virus in the development and/or progression of EBV+<unk>  is unclear. Immunodeficiency is also seen with<unk> , but it is a sequela and not a predisposing factor.
Angioimmunoblastic T-cell lymphoma
Mature T-cell lymphoma
Pleomorphic T-cell lymphoma
Nodal marginal zone B cell lymphoma
Anaplastic large-cell lymphoma
Mixed-cell lymphoma
Pediatric-type follicular lymphoma
Peripheral T-cell lymphoma