t- cell lymphomas

7/29/2019 T- Cell Lymphomas

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T- CELL

NEOPLASMS


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Case No 8

8 yrs old female presented with cervical

lymphadenopathy


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TdT


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CD3


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CD20


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CD79a


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Precursor T lymphoblastic

leukemia / lymphomaThis neoplasm is typically composed of small

to medium-sized blast cells with scant

cytoplasm, moderately condensed todispersed chromatin and inconspicuous

nucleoli. Nuclear convolutions may be

prominent and mitotic figures are numerous.


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Epidemiology

Precursor T-ALL (Leukemia) comprises

about 15% of childhood ALL. It is more

common in adolescents than youngerchildren and more common in males than

females.

Precursor T lymphoblastic lymphoma

comprises approx 85 90% of

lymphoblastic lymphomas


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Immunophenotype

Pan T (UCHL1) +

Cytoplasmic CD3+ (linage specific)


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Case No 9

40 years old male presented with

erythematous, scanty and pruritic lesions


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Mycosis Fungoides (MF)

MF is a mature T-cell lymphoma presenting in

the skin with patches / plaques and

characterized by epidermal and dermalinfiltration of small or medium sized T-cells

with cerebriform nuclei.


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So-called Pautrier micro abscesses

Consisting of aggregates of cerebriform cells

in the epidermis are highly characteristic but

are only seen in proportion of the cases.Epidermal involvement with single cell

exocytosis is more common. In the dermis,

infiltration may be patchy, band-like ordiffuse depending upon the stage of the

disease.


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Immunophenotype / Genetics

Pan T (UCHL1) ----- +

CD3 ----- +

CD4 ----- +

CD8 ----- -

T cell receptor genes are clonally

rearranged in most cases.


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Case No 10

40-year-old woman with lymph node

enlargement


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Anaplastic Large Cell Lymphoma

(ALCL)ALCL is a T-cell lymphoma consisting of

lymphoid cells that are usually large with

abundant cytoplasm and pleomorphic oftenhorseshoe shaped nuclei.


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H&E stained ALCL section. Mag: 40X


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Epidemiology

ALCL accounts for approx 3% of adult NHLS

and 1030% of childhood NHLS. ALK-

positive ALCL is most frequent in the firstthree decades of life and shows a male

preponderance


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Immunophenotype / GeneticsCD30 ----- +

ALK ----- +/-

EMA ----- +

UCHL1 / CD3 ----- +/-

Approx 90% of ALCLs show clonalrearrangement of the T-cell receptor genes

irrespective of whether they express T-cell

antigens or not.

Immunoperoxidase stain on a section of ALCL with CD 30 (Ki 1) antibody Note


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Immunoperoxidase stain on a section of ALCL with CD 30 (Ki-1) antibody. Note

Strong positive membrane labeling of large atypical cells. Mag: 20X

Immunoperoxidase stain on a section of ALCL with ALK protein


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Immunoperoxidase stain on a section of ALCL with ALK protein.

Note characteristic nuclear and cytoplasm staining of anaplastic cells. Mag: 40X


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Case No 11

50 years old male presented with

generalized lymphadenopathy and hepato-

splenomegaly.


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Angioimmunoblastic T-cell

Lymphoma (AILT)AILT occurs in the middle aged and elderlywith an equal incidence in males and females.

It is one of the more common specific

subtypes of peripheral T cell lymphomas,

accounting for approx 15

20% of cases or 1

2% of all NHLs.


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Sites of Involvement

Patients usually present with generalized

peripheral lymphadenopathy,

hepatosplenomegaly and frequent skin rash.

BM is commonly involved upon biopsy.


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Clinical Features

AILT usually presents with advanced stage

disease, systemic symptoms and polyclonal

hyper-gammaglobulinemia.


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Histopathology

The lymph node architecture is partially

effaced with regressed follicles. Theparacortex is diffusely infiltrated by apolymorphous population of small to medium

sized lymphocytes usually with clean to palecytoplasm and distinct cell membranes. Theabnormal lymphoid cells are admixed withsmall, reactive lymphocytes, eosinophils,

plasma cells, histiocytes and increasednumber of follicular dendritic cells. Highendothelial venules are abundant and showarborisation.


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Pan T (UCHL1) +

CD3 +

T cell receptor genes are rearranged in 75%

of the cases.


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Prognosis

The clinical course is aggressive with a

median survival of less than 3 years.


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Case No 12

50 yrs old male presented with cervical

lymph node enlargement


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http://www.pathconsultddx.com/pathCon/largeImage?pii=S1559-8675(06)70453-3&figureId=fig1


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Peripheral T cell Lymphoma

(PTCL) unspecifiedA number of distinctive entities have been

defined which correspond to recognizable

subtypes of T-NHL. Once these have beenseparated, there remains a large group of

predominantly nodal (and occasionally extra

nodal) T cell lymphomas which constitute asignificant proportion of the PTCL. We

collectively refer to them as PTCL.


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Epidemiology

These tumors accounts for approx half of

the peripheral T-cell lymphomas. Most

patients are adults but children may also beaffected M:F ratio is 1:1


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Site of involvement

Most patients present with nodal

involvement but any site may be affected

and patients often have generalized diseasewith infiltration in the BM liver, spleen and

extra nodal tissues like skin.


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Histopathology

These lymphomas show diffuse infiltrates.

The cells in most cases are medium sized or

large with irregular, pleomorphic nucleiwhich may be hyperchromatic or vesicular

with prominent nucleoli and many mitosis.

Clear cells and RS like cells are oftenpresent. High endothelial venules are

increased and arborising vessels may be

seen.


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Pan T (UCHL1) +

CD3 +

CD4 +CD8 -

CD30 +/-

T cell receptor genes are clonally rearranged inmost cases


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Prognosis

They are among the most aggressive of

NHLs. Patients often respond poorly to

therapy, relapses are frequent and OS at 5years is low (20 30%)

t- cell lymphomas

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