HLS Pathology 3 : Lymphoid Neoplasms

(T/F)

All lymphoid neoplasms can spread to lymph nodes & other tissues (liver, spleen, bone marrow, and peripheral blood)

True

B-cell markers?

CD19, CD79, and CD20

T-cell markers?

CD3 (either CD4 or CD8)

marker of early lymphoid origin (B & T lymphoblasts)?

TdT (Terminal deoxynucleotidyl transferase)

most of B-cell lymphomas are caused by …

Genetic errors that occur during antigen receptor gene rearrangement and diversification.

Relationship between Lymphoid neoplasms and immune system?

Lymphoid neoplasms

1) Can cause Immunodeficiency ( ↑ susceptibility to infection)

2) Can cause Autoimmunity

3) Inherited or acquired immune deficiencies ↑ the risk for the development of certain lymphomas (usually EBV associated)

The Neoplasm that composed of immature B (pre-B) or T (pre-T) cells is called?

Acute Lymphoblastic Leukemia/Lymphoma (ALL)

The most common cancer of children

Acute leukemia (peak : 3 years)

Pre-T Cell ALL genetic features ?

• NOTCH1 mutations
  → NOTCH1 is essential for T cell development

• CDKN2A mutations
  → Tumor suppressor gene deletion/mutation

Pre-B Cell ALL genetic features ?

• Hyperdiploidy
  → >50 chromosomes per cell

• t(12;21)
  → Translocation between chromosomes 12 and 21

• t(9;22)
  → Translocation between chromosomes 9 and 22
  → Forms the Philadelphia chromosome
  → BCR-ABL fusion gene, associated with poor prognosis

(ALL) Clinical features

1) Symptoms related to depression of marrow function; anemia, neutropenia & bleeding.

2) Mass effects → neoplastic infiltration; bone pain

3) CNS manifestations headache, vomiting, and nerve palsies.

The leading cause of cancer deaths in children

ALL

N.B: its an aggressive but curable (85% cure rate in children)

Worse prognosis in ALL according to

-age

-WBC count

-cause

▹ Younger than 2

▹ Older than 10

▹ PB WBC count > 100,000

▹ t(9;22)

Favorable prognosis in ALL

-age

-WBC count

-cause

▹ Age between 2-10

▹ PB Low WBC count

▹ Hyperdiploidy

▹ t(12;21)

The most common leukemia of adults in the West

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL)

The tumor cells express …. in SLL and MCL

CD5

A neoplasm of mature B cells cause expression of…

CD20

(CLL/SLL) Clinical features?

1- Peripheral lymphocytosis (>5000)

2- Indolent disease but cure may only be achieved with hematopoietic stem cell transplantation (HSCT)

3- 10-15% develop autoimmune hemolytic anemia & thrombocytopenia.

4- Old age often asymptomatic , But symptoms are nonspecific

Pathogenesis of Follicular Lymphoma

t(14;18) fuses of BCL2 gene on chromosome 18 to the IgH locus on chromosome 14 → inappropriate “overexpression” of BCL2 protein (an inhibitor of apoptosis) → contributes to cell survival

CD10 is expressed in…

1-Burkitt lymphoma

2-ALL

3-some DLBC

Follicular Lymphoma Immunophenotype?

▹ B-cells markers (mature B cell neoplasm)

▹ CD10 → GC marker

(T/F)

Follicular Lymphoma is a curable disease

False

Prolonged survival, not curable disease (indolent)

(T/F)

40% of follicular lymphoma transform into DLBCL, dismal prognosis

true

(T/F)

Mantle Cell Lymphoma and Follicular Lymphoma occur in >50 of age

True

Mantle Cell Lymphoma Pathogenesis

t(11;14)→ fuses the cyclin D1 gene to the IgH locus → overexpression of cyclin D1→ stimulates growth by promoting the progression of cell cycle from G1 to S phases)

Mantle Cell Lymphoma Immunophenotype

1) B cell markers

2) CD5 (as CLL/SLL)

3) Cyclin D1 ( not expressed in CLL/SLL)

The median survival in MCL?

4-6