t cell and nk-cell neoplasms

T-cell and NK-cell neoplasms

DrAbdullah A.Hashish

Pre-test.

• What is the role of stem cell differentiation stage in the lymphoid classification? Give examples?

• True or False:– Hodgkin lymphomas are derived from neoplastic T-cell.– B-cell leukemias/lymphomas are more aggressive than T-

cell leukemias/ lymphomas.– NK-cell lymphomas are more aggressive than B-cell

lymphomas.• Short account about Sezary syndrome.

Post-natal lymphopoiesis in human

NK cells

• NK cells are defined as:1. cytotoxic cells. 2. with the predominant morphology of large granular

lymphocytes (LGLs). 3. neither productively rearrange any of the genes encoding

the T-cell receptor (TCR) chains 4. nor express on their surface the CD3-TCR complex5. express the CD56 (N-CAM), CD335 (NKp46), and CD16

(FcγRIIIA), antigens in humans.6. can kill cells not expressing major histocompatibility

complex (MHC) class I or class II antigens.

Morphology of NK cells

• Size of LGLs: medium- to large.• Nucleus: round or indented. • Chromatin: condensed.• Nucleoli: usually prominent.• Cytoplasm: abundant and contains a variety of

organelles and granules.• many NK cells have the morphology typical of LGL, a

significant proportion of NK cells are agranular and indistinguishable from other lymphocytes.6

T-cell neoplsms

1.Immature.1.Lymphoblastic

leukemia/lymphoma.2.Mature.– Different subtypes.

T-cell lymphoblastic leukemia/lymphoma

•Morphology:–Size: Medium to large cells.–Chromatin: finely stippled.–Cytoplasm: scanty.


• Immunophenotyping:– TdT+, – cytoplasmic CD3+,– CD7+, – CD34+/-, CD2+/-CD1a+/-, CD5+/-,– CD4+/CD8+ or CD4-/CD8-– CD10-/+.


• Genotyping:–Abnormalities in:1. TCR loci at:

1. 14q11 (TCR-α), 2. 7q34 (TCR-β), or 3. 7p15 (TCR-γ),

2. t(1;14)(p32-34; q11) involving TAL1

Mature T and NK cell neoplasms

1. Leukemias: 1. T-cell prolymphocytic leukemia. 2. T-cell large granular lymphocytic leukemia.

2. Lymphomas/Lymphoproliferative Disorders:– Many subtypes.

T-cell prolymphocytic leukemia

• Morphology:– Size: Small to medium. – Cytoplams: cytoplasmic protrusions or blebs.

• Immunophenotyping:– TdT-, – CD2+, CD3+, CD5+, CD7+, – CD4+ and CD8- is more common than CD4- and

CD8+, but can be CD4+ and CD8+

T-cell large granular lymphocytic leukemia

• Morphology:– Cytoplasm: • Abundant.• Sparse azurophilic granules

• Immunophenotyping:– CD2+, CD3+, CD5+, CD7+,– CD8+/-, CD16+/-, CD57+/-, – CD4 -/+,– CD56-.

Lymphomas/Lymphoproliferative Disorders

• Extranodal T/NK-cell lymphoma, nasal type “angiocentric lymphoma”–Immunophenotyping:• CD2+, cytoplasmic CD3+, CD7, CD56,CD4-, CD8-

& EBV+.–Genotyping:• TCR rearrangements usually NEGATIVE• EBV present by in situ hybridization.


• Cutaneous T-cell lymphoma (mycosis fungoides):– Morphology:• Size: Small to large cells.• cerebriform nuclei.

– Immunophenotyping:• CD2+, CD3+, CD4+, CD5+, CD26+• CD7+/-, CD8-, CD25-.


• Sezary syndrome:–mostly typical as Cutaneous T-

cell lymphoma (mycosis fungoides)


• Adult T-cell leukemia/lymphoma:–Morphology: •Highly pleomorphic with multilobed

nuclei.–Immunophenotyping:•CD2+, CD3+, CD5+, CD25+, CD7-, •CD4+CD8- more often than CD4-CD8+


• Hepatosplenic T-cell lymphoma:–Morphology:• Size: Small to medium cells.• Chromatin: condensed.• round nuclei.

–Immunophenotyping:• CD2+, CD3+, CD5+, CD7+/-• CD4-, CD8+/-.


• Enteropathy associated T cell lymphoma:–Morphology: • Size: Medium to large cells.• prominent nucleoli.• Cytoplasm: abundant pale, invading mucosal

membranes of the small intestine.– Immunophenotyping: • CD3+, CD7+, CD 103+, CD30+ (most cases),• CD8+/-, CD4-, CD5-, TCRβ+/-.

NATURAL KILLER (NK) CELL NEOPLASMS

• Large granular lymphocytic leukemia.• Aggressive NK-cell leukemia.• Extranodal NK-cell lymphoma, nasal type “angiocentric

lymphoma”.• Immunodeficiency-associated lymphoproliferative

disorders.– Lymphoproliferative disorders associated with primary

immune disorders. – Lymphomas associated with HIV infection.

• Post-transplant lymphoproliferative disorders (PTLDs).


• Large granular lymphocytic leukemia:– Morphology: • Cytoplasm: Abundant cytoplasm and sparse azurophilic

granules.– immunophenotyping: • TdT-, CD2+, CD 7+, CD11b+, CD16+, CD56+,• CD3-, CD4-, CD5-/+, CD8-/+, CD57+/-.

– Genotyping: No TCR rearrangement• Aggressive NK-cell leukemia (show the same but

EBV present).


• Extranodal NK-cell lymphoma, nasal type “angiocentric lymphoma”–Immunophenotyping: •CD2+, cytoplasmic CD3ε +, CD 56, CD 7+•CD4-, CD5-/+, CD8-.

–Genotyping:•No TCR rearrangement, EBV present.


• Post-transplant lymphoproliferative disorders (PTLDs):–Early lesions: plasmacytic hyperplasia

(PH) and infectious mononucleosis (IM)-like.–Polymorphic PTLD.–Monomorphic PTLD.

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t cell and nk-cell neoplasms

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