W11 - Lymphoma 1

Question 1

What % of lymphomas is Hodgkin’s and Non-Hodgkin’s?

Answer 1

NHL 80%
HL 20%

Question 2

Where are lymphomas found (4)?

Answer 2

1. Lymphatic system = LNs, BM, and/or blood
2. Lymphoid organs = spleen, GALT
3. Skin = often T cell disease
4. Rarely anywhere; immune privilege sites CNS, ocular, testes

Question 3

ALL is malignancy of ___________ cells

MM is malignancy of ____________ cells

Mantle cell lymphoma is a type of _______ lymphoma, and is malignancy of ___________

Answer 3

ALL is malignancy of B-cell precursor cells

MM is malignancy of plasma cells

Mantle cell lymphoma is a type of Non-Hodgkin’s lymphoma, and is malignancy of Mantle zone B cell

Question 4

Name 3 mechanisms in which lymphocytes contribute to potential mutations giving rise to lymphomas?

Answer 4

1. lymphocytes undergo somatic hypermutation + recombination for increasing Ig & T cell receptor diversity + Ig class switching = errors + new point mutations
2. Rapid cell proliferation in GC for rapid response to infection = risk of DNA replication errors
3. Dependent on apoptosis (90% of lymphocytes die in GC) to create ab specificity % eliminate self-reactive clones = apoptosis switched off in GCs

Question 5

Describe how translocations between Ig promoters + oncogenes are implicated in lymphoma.

Name 4 oncogenes.

Answer 5

Recombination moves Ig Heavy chain promoter on chr 14 to chr 8, sitting behind an intact oncogene => overexpress of ONCOGENE rather than a useful antibody

* the oncogene could be anti-apoptotic or pro-proliferative.
* 4 oncogenes: bcl2, bcl6, myc, cyclinD1

Question 6

Name 3 main mechanisms of rare NHL subtypes

Answer 6

1. Constant antigenic stimulation
2. Viral infection
3. Loss of T cell function & EBV infection

Question 7

Chronic antigen stimulation causing NHL:

• Name 3 autoimmune conditions causing B cell NHL Marginal Zone subtype (MZL)
• where is the MZL found for each

Answer 7

1. Sjogren syndrome => MZL of stomach (MALT)
2. Hasimoto’s syndrome => MZL of thyroid
3. Coeliac disease => small intestine EATL

Question 8

Chronic antigen stimulation causing NHL:

• Name 1 infection causing B cell NHL Marginal Zone subtype (MZL)
• where is the MZL found for each

Answer 8

H pylori => MZL of stomach (Gastric MALT)

Question 9

Direct viral integration causing NHL:

• Name 1 virus causing T cell NHL
• Lifelong risk of developing T cell NHL with infection with this virus

Answer 9

• HTLV1 = retrovirus that infects T cells by vertical transmission
• Risk of Adult T cell leukaemia lymphoma (ATLL) is 2.5%
• ATLL is a subtype of T cell NHL

Question 10

Loss of T cell function + EBV infection causing B NHL:

• 2 risk factors for losing T cell function
• mechanism of B NHL

Answer 10

1. HIV (uncontrolled)
2. Iatrogenic immunosuppression (i.e. post-transplant lymphoproliferative disorder)

• loss of cytotoxic T cell function can cause failure to eliminate EBV-driven proliferation of B cells

Question 11

Regarding lymphoma aetiology, which of the following is NOT true?
A) Marginal zone lymphoma (MZL) of parotid is linked to Sjogren syndrome
B) MZL(MALT) of stomach is linked to H pylori infection
C) Ciclosporin therapy is linked to EBV-driven post transplant lymphoma
D) Chronic EBV infectionis linked to adult T cell leukaemia/lymphoma

Answer 11

D) incorrect. This is due to viral infection by T cells.

Question 12

In certain NHL subtypes, chromosome translocations involving a proto-oncogene are seen. Which statement is NOT true?
A) Follicular NHL: IgH-BCL2
B) Mantle cell lymphoma: IgH-Cyclin D1
C) Follicular NHL: BCR-ABL1
D) Burkitt lymphoma: IgH-cMYC

Answer 12

C - this is a myeloid one (CML)

other ones are lymphomas and involve an oncogene (BCL2, Cyclin D1, cMYC) that’s been moved to a B cell active promoter (IgH)

Question 13

LN biopsy: Reed Sternberg cells are present with a background of chronic inflammatory cells and eosinophils. Name the disease

Answer 13

Hodgkin’s lymphoma