Micrograph showing PTGCs. H&E stain. PTGC is diagnosed by surgical excision of the affected lymph node(s), and examination by a pathologist. The differential diagnosis includes non-neoplastic causes of lymphadenopathy (e.g. cat-scratch fever, Kikuchi disease) and malignancy, i.e. cancer. Microscopic appearance PTGCs is characterized by: * follicular hyperplasia (many follicles), * focally large<unk><unk> , with poorly demarcated<unk> <unk> (GC)/mantle zone interfaces (as GCs infiltrated by mantle zone lymphocytes), and * an expanded mantle zone.
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