Epstein-Barr virus-associated large B-cell lymphoma transformation in marginal zone B-cell lymphoma: a series of four cases.

Aims: To present four examples of clonally related Epstein-Barr virus (EBV)-associated large-cell transformation of marginal zone lymphoma (MZL) (of nodal, extranodal and splenic types), occurring 120, 11 and 5 months after the initial diagnosis in three instances, and concurrently in one case; and to discuss several interesting features of EBV infection.

Methods And Results: Somatic mutations were detected by use of a customised panel for next-generation sequencing and polymerase chain reaction studies of IgH in both low-grade and high-grade components of each case. In case 1, the initial biopsy of nodal MZL showed scattered EBV-positive cells, which might constitute an indication of EBV-induced progression. Case 2 showed heterogeneous EBV expression, a phenomenon attributable to loss of the EBV episomes during cell division, or to a secondary superinfection or reactivation of the virus. In case 3, p53 overexpression related to gene mutation and EBV-encoded small RNAs were identified in the same neoplastic component. In case 4, the mucosa-associated lymphoid tissue-type MZL and the high-grade component were identified concurrently in a patient previously treated with methotrexate for an autoimmune disorder.

Conclusion: These data suggest that the presence of EBV should be added to the list of potential markers to be analysed for MZL prognosis.