23 - Lymphoma

Question 1

Important subtypes

Answer 1

• B cell
• Follicular
• Small lymphocytic lymphoma
• Diffuse large B-cell lymphoma (DLBCL)
• Burkitt
• Hodgkin
• Gastric MALT
• Myeloma

Question 2

Laboratory studies (Traige)

Answer 2

• Microbiology
• Flow cytometry
• Histology (formalin fixation)
• PCR
• FISH
• Cytogenetics

Question 3

Fresh node triage

Answer 3

Cut surface smear and rapid H+E stain

Question 4

follicular lymphoma

Answer 4

• Germinal center expansion (CD10+, BCL6+)
• Lambda light chain restricted
• B cell (CD19+, CD20+)
• Follicular histology pattern

Question 5

Small lymphocytic lymphoma/leukaemia
(SLL/CLL)

Answer 5

Often leukaemic in addition to nodes

Question 6

Mantle cell lymphoma

Answer 6

Defined by overexpression of cyclin D1

Question 7

Germinal center markers

Answer 7

• CD10
• BCL6

Question 8

BCL2

Answer 8

• Anti-apoptotic marker
• Normal T cells, resting B cells

Question 9

Clonality

Answer 9

• Cells that are expressing the same light chains and kappa/lambda
• Expanded from common clone
• Assessed by flow cytometry (shows if kappa or lambda

Question 10

Lymphoma staging

Answer 10

• Renal, liver function
• HIV, HCV, HBV (infection due to reduced immunity)
• Bone marrow trephine
• CT scan (lesions)
• PET scan (metabolic activity)

Question 11

Indications for treatment

Answer 11

• Progressive disease or bulky disease
• Organ dysfunction
• Systemic B symptoms
• Cytopenias

Question 12

FDC network

Answer 12

Dense network of stromal cells that plays a key role in B-cell activation and antibody affinity maturation

Question 13

Follicular lymphoma transformation

Answer 13

• Can transform into DLBCL, sometimes to aggressive double hit lymphoma
• BCL2-IgH fusion seen in 90% FL
• Additional MYC- or BCL6- break apart associated with transformation and poor prognosis (is the second hit in ‘double hit’)

Question 14

FL mutations

Answer 14

t(14;18)(q32;q21)

Question 15

R-CHOP

Answer 15

Rituximab (anti-CD20) to treat FL

Question 16

Symptoms of Hodgkin Lymphoma

Answer 16

• Slow swelling of neck
• Night sweats
• Weight loss
• Fevers

Question 17

Morphology of hodgkin lymphoma

Answer 17

• Hodgkin, R-S cell variants (hallmark of HL)
• Fibrosis, heterogeneous background

Question 18

HL immunophenotype

Answer 18

• CD30+/CD15+/CD45-
• CD20-/CD3-/
• PAX5weak+/EBER+

Question 19

Hodgkin lymphoma diagnosis

Answer 19

• Flow cytometry not useful
• PET
• Bone marrow trephine

Question 20

CD45

Answer 20

• Stains B cells, T cells and NK cells
• Negative indicative of HL

Question 21

PAX5

Answer 21

B cell TF

Question 22

Hodgkin lymphoma

Answer 22

• Presents in younger people
• Unique neoplastic cell with heterogenous background
• Some associated with EBV
• usual IHC: CD45-, CD30+, CD15+ (crippled B cell)
• No clonality by flow
• High cure rate

Answer 23

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