Diffuse large B-cell lymphoma
Clinical features § 40% initially confined to extranodal sites § Rapidly enlarging , often symptomatic mass
Aetiology § Immunodeficiency is a risk factor § DLBCL in immunodeficiency are more often EBV positive than in sporadic DLBCL
Morphology § Architecture is replaced § Peri-nodal soft tissue is infiltrated § Large transformed lymphoid cells § Morphologic variants o Centroblastic o Immunoblastic o T-cell/ histiocyte rich o Anaplastic
Immuno § Pan B-markers § Surface and cytoplasmic Ig may be positive § CD30 negative, except for anaplastic § High proliferation rate (>40%)
Cytogenetics § Microarray technology can divide into § Germinal centre B cell like – better prognosis § Activated B cell like § Type 3
Ann Arbor Stage 1 : 1 LN region or 1 extralymphatic site Stage 2 : 2 or more LN sites on same side of diaphragm or contiguous involvement of 1 extralymphatic site and LN Stage 3 : LNs on both sides of diaphragm, may include spleen Stage 4 : Extranodal sites
A : no systemic symptoms B : systemic symptoms E : sinlge extranodal site S : splenic involvement X : Bulky disease >1/3 widening of mediastinum at T5-6, nodal mass >10cm
International Prognostic Index
Other risk factors § Poor § High proliferative rate – Ki67 marker of high proliferation § Bcl-2 § P53 § Good § Bcl-6
Treatment § Depends on stage of disease Stage I § 3 cycles R CHOP § Followed by involved field radiotherapy
Stage II-IV § R-CHOP currently standard treatment § Rituximab binds CD20 and may work in part by down regulating BCL2
Relapsed/ refactory § Long term overall survival <10% § Second line chemo DHAP / ICE / EPOCH § Auto-SCT – high dose therapy followed by auto is effective only in those who have shown some response to conventional dose second line chemo prior to auto § Allo § Y90 labelled monoclonal antibody therapy
Assessment of response § PET § Negativity after 2-4 cycles strongly correlates with durable remission § Positive patients have a high likelihood of relapse – consider for high dose therapy § Follow up § 3 monthly follow up (FBC / LDH) for the 1st 2-3 years with 6 monthly CT scans § Years 4/5 – 6 monthly follow up § Annual follow up thereafter Mediastinal (thymic) large B-cell lymphoma
Subtype of DLBCL arising in the mediastinum
Clinical Features § More common in women age 20-40 § Signs and symptoms secondary to a large anterior mediastinal mass § May have impending SVC obstruction § Progresses to involve, kidneys, ovaries, liver, spleen and CNS § EBV is not present
Morphology § Massive diffuse proliferation associated with compartmentalising fibrosis
Immunophenotyp § Pan B-markers § Lack surface Ig § May mimic Hodgkins with interspersed lymphocytes and eosinophils but this expresses CD45 in contrast to classical HD § Recent gene expression profiling shows that it is distinct from DLBCL and shares many components with Hodkin Reed-Sternberg cells
Treatment § R CHOP usually followed by involved field radiotherapy § Prognosis largely dependant on stage of disease at presentation § PET currently under evaluation to distinguish residual disease from fibrosis
Intravascular large B cell lymphoma
Subtype of DLBCL – lymphoma cells only in the lumina of small vessels
Sites of involvement § Usually widely disseminated at diagnosis
Clinical Features § Symptoms result from occlusion of small vessels by tumour cells § May have B-symptoms
Morphology § Neoplastic cells lodged in lumina of small vessels, may be fibrin thrombi § Express B-cell markers
Treatment § Poor prognosis partly related to delays in diagnosis |
Haemato-oncology > Mature B Cell neoplasms >