T cell lymphomas Flashcards
Primary cutaneous CD30+ Tcell lymphoproliferative disorders:
ALCL
Lymphomatoid papulosis
Spectrum of disorders characterised by large CD30+ T cells
Older males
Primary cutaneous ALCL: skin nodules which may regress but recur, chronic disease (relapsing remitting)
LyP: spontaneously regressing papules on extremeties
Local excision and radiation therapy
Can progress to lymphoma and extra-cutaneous disease (in that order)
5 yr survival 90%
Primary cutaneous ALCL histology
Lymphomatoid papulosis histology
Primary cutaneous ALCL: diffuse dermal infiltrate to subcutaneous tissue of large cells
Little epidermotropism
Pseudoepitheliomatous hyperplasia, ulceration
LyP: wedge-shaped dermal infiltrate of large cells with reactive bg
Type A - RS-like cells with inflamm cells (looks like classical HL)
Type B - cerebriform lymphocytes, less inflamm
Type C- confluent large cells but regress
Primary cutaneous CD30+ve T cell lymphomas Immuno
T cell markers
CD30+ve (except LyP type B)
Usu CD4 BUT…
…..Cytotoxic phenotype (TIA-1, granzyme B, perforin)
Abberent T cell phenotype common
ALK -ve (**If ALK +ve, must be systemic variant)
NB in primary cutaneous, ALK-1 negativity does not confer bad prognosis
Cytogenetics: clonal TCR rearrangements
Anaplastic large cell lymphoma (systemic):
Definition
Clinical
Systemic (nodal) T cell lymphoma with CD30 +ve large pleomorphic T cells, and involves nodal sinuses
Bimodal age: children (ALK +ve), older adults (ALK -ve)
Aggressive, prognosis related to ALK +vity (+ve better prognosis)
Treated with chemo and anti-CD30 monoclonal ab
ALCL histo
Immuno
Cytogenetics
Differentials
Confined to sinuses or nodal effacement
Hallmark cells: horseshoe, doughnut cells with prominent nucleoli and abundant cytoplasm
CD30+ tumour cells
T-cell or null phenotype
ALK +/-, CD4 +ve, CD30 +ve, cytotoxic granule associated proteins (TIA-1, perforin) +ve, CD56 may be +ve
Genetic: t(2;5) ALK-NPM1
Differentials: metastatic carcinoma/ melanoma
Hodgekins
PTCL NOS
PTCL NOS clinical
Nodal and extranodal
Adults
Lymphadenopathy, B symptoms
Aggressive, treated with chemo
PTCL NOS histology
Effaced arch
Polymorphic background
Tumour cells c clear cytoplasm, varying size, RS-like cells
Immuno: variable T cell antigens
Cytogenetics: TCR rearrangement
Extranodal NK/T cell lymphoma, nasal type
Clinical features
Usu extranodal
EBV related
Most derive from NK cells, some from cytotoxic T cells
Adult males
Nasal symptoms, B symptoms
Extranodal NK/Tcell lymphoma, nasal type
Histology
Angiocentric, angioinvasive, angiodestructive infiltrate of atypical lymphocytes
NK cell: CD2, CD56, TCR -ve, no clonal TCR rearrangement
Cytotoxic T cell: CD2, 3 TCR +ve, clonal TCR rearrangement
Both have cytotoxic granule associated proteins,
both EBV +ve
Extranodal NK/Tcell lymphoma, nasa type
Differntial diagnoses
Wegener’s granulomatosus
Lymphomatoid granulomatosis (EBV +ve B cells)
DLBCL
Subcutaneous panniculitis-like T cell lymphoma
Subcutaneous panniculitis-like T cell lymphoma
Lymphoma of cytotoxic T cells (CD8+) producing painless subcutaneous nodules in extremeties or trunk
Variably indolent to aggressive
Young adults
Haemophagocytic syndrome (splenomegaly, cytopenia, hypertriglyceridaemia)
SPLTCL histology
Lobular panniculitis
Tumour cells rim fat spaces
Karyorrhexis, fat necrosis
CD8, TCR ab, cytotoxic proteins
Hepatosplenic T cell lymphoma
Massive splenomegaly without lymphadenopathy
Enteropathy associated TCL (EATL)
Type 1
Type 2
Aggressive
Can cause perforation of small bowel
Type 1 ass c coeliac. Large cells, c necrosis and inflamm cells
Type 2: smaller cells, no necrosis/inflamm
T cells with clear cytoplasm infiltrates mucosa
Epidermotropism, lymphoepithelial lesions, gland destruction
Type 1: CD2 +ve, CD56 -ve
Type 2: CD8 +ve, CD56 +ve
TIA-1, granzyme B +ve
EATL differential diagnoses
Coeliac disease
MALT lymphoma
DLBCL
PTCL NOS
Mycosis fungoides clinical
Older males
Protracted clinical course
Scaly rash often on trunk
Tumour cells are CD4 +ve T cells of skin-associated lymphoid tissue
Usu skin-based therapy, chemo for advanced disease
Can transform to large cell lymphoma
Sezary syndrome: generalised erythroderma and lymphadenopathy
Mycosis fungoides histology
Patch stage: epidermotropism, mild dermal infiltrate of cerebriform lymphocytes
Plaque stage: Dense band dermal infiltrate, epidermotropism, Pautrier’s abscesses
Tumour stage: Dense dermal infiltrate, less dermotrophism
Large cell transformation: >25% large cells in dermis, tumour cells acquire CD30+
Erythroderma: mild dermal infiltrate, pautrier’s abscesses, Sezary cells in peripheral blood
Immuno: CD4+, CD7 -ve
CD30 +ve
Cytotoxic granule-associated proteins (TIA-1, perforin) -ve c.f. ALCL
Molecular: clonal TCR rearrangement
The same TCR rearrangement in 2 separate bxs in supportive of MF
NB: in dermatopathic lymphadenopathy, look for MF cells
Mycosis fungoides variants
Pagetoid reticulosis: localised, epidermal infiltrate only
Granulomatous slack skin: dermal infiltrate, granulomas
Folliculotropic MF: perivascular and periadnexal involvement with mucinosis (involved eccrine glands = syringotropic MF)
Pagetoid reticulosis
Essentially in-situ ALCL
Must be actively treated as will progress to ALCL proper
Differntial diagnosis: Malignant melanom
Sezary syndrome
Erythroderma
Circulating Sezary cells - characteristic cells
CD3+ (like MF)
CD30 -ve (unlike MF)
T cell lymphomas general points
All BLASTIC T cell lymphomas are MUM1 +ve
CD43 stains T cells but also myeloid cells - histiocytic lymphomas are positive
Jessner’s
Erythematous/brown discoid lumps on face, neck, thorax
Matuer T cells around vascular plexi and hair follicles
