Category Archives: WHO Classification

Organ Systems, Bone Marrow, Lymph Node, WHO Classification

Chronic Lymphoproliferative Disorders of NK Cells

This is considered a provisional entity by the WHO classification in 2008.   In many ways this entity is similar clinically to T-LGL leukemia, but there are no rearrangements of immunoglobulin or T-cell receptors since the cells are NK cells.
Characteristic Immunophenotypic Profile
Marker
Comment
Surface CD3 negative.  Cytoplasmic CD3ε is often positive.
Usually weak expression
TIA-1
Positive
Positive
+/- May show diminished of loss of expression.
+/- May show diminished of loss of expression.
CD57
+/- May show diminished of loss of expression.
May show aberrant uniform expression.
References
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.
Organ Systems, Lymph Node, WHO Classification

Anaplastic Large Cell Lymphoma, ALK-

Immunophenotypic Expression Pattern
Marker
Comment
Negative, by definition.
Positive, should be strong and of equal intensity.
+/- more often positive than CD5
+/- more often positive than CD5
Usually Positive
-/+
+/-
Negative (rare +)
Negative
Often Positive
EBV (EBER)
Negative.  If positive, it should raise concern of a classical Hodgkin lymphoma.
Often Positive
Perforin
Often Positive
TIA-1
Often Positive
Negative
Negative.  If positive, then this should raise the possibility of classical Hodgkin lymphoma.
References
Parker, A., et. al.  “Best Practice in Lymphoma Diagnosis and Reporting.”  British Committee for Standards in Haematology, Royal College of Pathologists.  April, 2010.
 
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.  pp. 312-19.
Organ Systems, Lymph Node, WHO Classification

Anaplastic Large Cell Lymphoma, ALK+

Immunophenotypic Expression Pattern
Marker
Comment
Variably Positive (up to a 1/3rd may be Negative)
Positive in >50% of cases.
Positive by definition.  Nuclear and cytoplasmic expression is c/w t(2;5).  ALK may show nuclear, membraneous, or cytoplasmic localization dependent upon what type of translocation is involved.
Positive
Positive (70%)
Negative in >75% of cases (rare +)
Positive (70%)
Negative (rare +)
+/- (70%)
Negative (rare +)
Negative
Positive (majority)
EBV (EBER)
Negative
Perforin
Usually Positive
Usually Positive
TIA-1
Positive
Negative
Negative
References
Parker, A., et. al.  “Best Practice in Lymphoma Diagnosis and Reporting.”  British Committee for Standards in Haematology, Royal College of Pathologists.  April, 2010.
 
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.  pp. 312-19.
Organ Systems, Lymph Node, WHO Classification

Angioimmunoblastic T-Cell Lymphoma

Immunophenotypic Expression Pattern
Marker
Comment
Positive
Positive
Positive
Positive
Positive
Positive (often numerous reactive T-cells will be present)
Positive in the neoplastic cells in ~50% of cases
CXCL13
Positive in a majority of cases (marker of follicular helper T-cells)
EBV (EBER)
Positive in reactive B-cells
Negative
Expanded FDC network
It is not uncommon for some of the T-cell markers to be dropped.
References
Parker, A., et. al.  “Best Practice in Lymphoma Diagnosis and Reporting.”  British Committee for Standards in Haematology, Royal College of Pathologists.  April, 2010.
Organ Systems, Lymph Node, WHO Classification

Peripheral T-Cell Lymphoma, NOS (PTCL-NOS)

PTCL-NOS is a heterogeneous group of mature T-cell lymphoproliferative disorders, which do not fit well into other defined categories, and have a generally poor outcome.  While there may be a lot of variability to the IHC findings, the following are some general characteristics:
 
  • CD4>CD8 expression.
  • Frequent loss of antigen expression from T-cell markers (CD4, CD5, CD7, CD8, CD52)
  • CD30 is usually negative
  • CD56 is usually negative
  • CD10 is usually negative
  • CLCX13 – negative
  • BCL6 – negative
References
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.
Organ Systems, Bone Marrow, Lymph Node, WHO Classification

Sezary Syndrome

Sezary syndrome (SS) is a generalized disease including a leukemia component.  Histologically, the skin findings may be similar to mycosis fungicides.
Immunophenotypic Expression Pattern
Marker
Comment
Positive
Positive
Positive (most cases)
Positive
Usually Negative
Usually Negative
References
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011. p. 299.
Organ Systems, Bone Marrow, Lymph Node, WHO Classification

Mycosis Fungoides

Mycosis Fungoides (MF) is an epidermotropic cutaneous T-Cell lymphoma and accounts for ~50% of cutaneous lymphomas overall.
 
Immunophenotypic Expression Pattern
Marker
Comment
Positive
Positive
Usually Positive
Positive
Usually Negative (some cases may be CD8+)
Usually Negative
TIA-1
Negative (rarely +)
References
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.
Organ Systems, Lymph Node, WHO Classification

Subcutaneous Panniculitis-Like T-Cell Lymphoma

This is a rare lymphoma (<1% of non-Hodgkin lymphomas), which presents as subcutaneous nodules on the skin.
Immunophenotypic Expression Pattern
Marker
Comment
Positive (usually)
TIA-1
Positive
Positive
Perforin
Positive
Negative
βF1
Positive (alpha beta T-cell phenotype)
EBV (EBER)
Negative
Refernces
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.  pp. 294-95.
Organ Systems, Bone Marrow, Lymph Node, WHO Classification

Hepatosplenic T-Cell Lymphoma

Immunophenotypic Expression Pattern
 
Marker
Comment
Positive
Positive
Negative
Negative
+/-
Negative (rare +)
Positive (+/-)
EBV (EBER)
Negative
Usually Negative
Perforin
Usually Negative (rare +)
TIA-1
Positive
Negative
Negative
References
Parker, A., et. al.  “Best Practice in Lymphoma Diagnosis and Reporting.”  British Committee for Standards in Haematology, Royal College of Pathologists.  April, 2010.
 
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.  pp. 292-93.
Organ Systems, Bone Marrow, Lymph Node, WHO Classification

Adult T-Cell Leukemia/Lymphoma

This is an aggressive lympho-proliferative disorder associated with Human T-Cell Leukemia Virus Type I (HTLV-1).  Most patients present with widespread lymphadenopathy and peripheral blood involvement.
Immunophenotypic Expression Pattern
Marker
Comment
Positive
Positive
Positive
Usually Negative
Usually Positive
Usually negative (there are occasional CD8+/CD4= or CD8+/CD4+ cases)
Strongly expressed in almost all cases.
May stain some large transformed cells.
Negative
TIA-1
Negative
Negative
HTLV-1
Positive.  There is no IHC stain, but this is an important test that can be done on the peripheral blood.
References
Hematopathology. [edited by] Jaffe, ES. 1st. ed. Elsevier, Inc. © 2011.  pp. 281-84.