<unk>  (PTGCs) is a reactive lymph node process of undetermined cause.
Progressive transformation of germinal centres
Atypical localization of immature precursors
Persistent polyclonal B-cell lymphocytosis
Lymphoid neoplasms with plasmablastic differentiation
Progressive osseous heteroplasia
Chronic active EBV infection
Extramedullary hematopoiesis
In situ lymphoid neoplasia