Senile EBV-associated B-cell lymphoproliferative disorder of indolent clinical phenotype with recurrence as aggressive lymphoma.

Senile EBV-associated B-cell lymphoproliferative disorder (LPD) was proposed as a new disease entity in 2003. This condition has a high incidence in elderly people without underlying immunodeficiencies, and is characterized by EBV-positive B-cell proliferation with a polymorphic composition. Histologically, the disease has two subtypes. The polymorphic LPD (PLPD) subtype has a preferable prognosis, whereas the large cell lymphoma (LCL) subtype involves aggressive disease progression. Reported herein is a case of senile EBV-BLPD with indolent clinical features and PLPD subtype in the initial phase that recurred as an aggressive lymphoma 3 years after the initial diagnosis. In the recurrent phase, Southern blotting confirmed monoclonal proliferation of large lymphoid B-cells. In both the initial and recurrent phases, polymerase chain reaction (PCR) yielded a single discrete band of a similar size due to an immunoglobulin heavy-chain gene rearrangement, indicating that the large lymphoid B-cells retained identical monoclonality throughout the histological progression and over the whole clinical course. These results suggest that the PLPD subtype is a histological finding in early phase senile EBV-BLPD and that the LCL subtype reflects the progressive phase of the disease.