Hairy cell leukaemia, lymphoma and myeloma

Question 1

What are the major testing methods involved in diagnosis of chronic B and T cell leukaemias and lymphomas?

Answer 1

• Immunophenotype and immunocytochemical cell characterisation provides good indication of type of disease
• PCR may identify Clonal cell surface receptor gene rearrangements

Question 2

What do cells express in hairy cell leukaemia?

Answer 2

• CD11c, CD25, CD103

- tested for using immunophenotyping

Question 3

Mutations in what gene are very common in hairy cell leukemia?

Answer 3

• BRAF (V600E)

- recommend testing for this if immunophenotyping is equivocal

Question 4

What is a lymphoma?

Answer 4

• Solid tumour of haematopoietic lymphoid cells within the solid tissue environment (lymph nodes)
• Sub-divided into Hodgkins and Non-Hodgkins lymphomas

Question 5

Provide some key features of Hodgkins lymphoma

Answer 5

• Characterised by presence of Reed-Sternberg cells
• Disease outcome = good (more than 80% of patients survive more than 5 years)
• Clonal IGVH rearrangements occur within the lymphoma cells but no other consistent molecular aberrations present

Question 5

What are the two common translocations seen in non-Hodgkins lymphoma?

Answer 5

• t(14;18): follicular lymphoma - bcl2 protein overexpressed following fusion of BCL2 gene with highly expressed IGH locus on chr14
• t(11;14): mantle cell lymphoma - fusion of IGH gene with cyclin D1 gene

Question 6

Where do non-Hodgkins lymphomas originate from?

Answer 6

B, T and NK cells

Question 7

What is myeloma?

Answer 7

• Malignant proliferation of bone marrow plasma cells
• Most common haematological malignancy (15% of all haematological cancers)
• Treatable, not curable

Question 8

What are 3 poor risk karyotypes associated with myeloma?

Answer 8

1. t(4;14)
2. Del13q
3. t(11;14)
   Deletion of TP53 assessed by FISH also associated with poor risk