Lecture 10 - Lymphoma Flashcards
1
Q
What is lymphoma?
A
- malignant disease in which lymphocytes proliferate in an uncontrolled manner leading to lymphocyte accumulation in lymph nodes and or in BM
- results in lymph node enlargement and marrow failure
2
Q
Epidemiology of lymphoma
A
- 5th and 6th most common cancers among males and females
- one of few cancers with rising incidence
- incidence of NHL in particulat increeases with age
3
Q
Types of lymphoma
A
B cell lymphomas are much more common than T cell lymphomas
4
Q
Some important facts
A
- each lymphocyte has one receptor for antigen on its surface and responds to only one antigen
- this receptor remains unchanged for the whole of the lymphocytes life
- thus in a lymphoma: all cells share the same receptor
- if its a B cell, all lymphoma cells express a single type of light chain, or express the same differentiation proteins on their surface
- if the parent B cell produces antibody, all lymphoma cells produce that same antibody: paraprotein
5
Q
Two types of lymphoma
A
- NHL
- HL
Based on standard morphology
6
Q
Identifyhing lymphocute population
A
- histology: small cells, little cytoplasm, dense chromatin
- flow cytometry: B cell markers, one type of light chain. CD34 marker is for HSC, CD19 for pro-B cell on , CD20 for pre-B cell on
- karyotype
- FISH
- PCR
7
Q
Gene translocations in lymphoma
A
- t (14,18): IgH/bcl2 -> apoptosis through bcl2 -> indolent lymphoma
- t (11:14): IgH/Bcl1 -> cell cycle via cyclin D -> mantle cell lymphoma
- t(8:14): IgH/c-myc -> cell cycle via cmyc -> Burkitts lymphoma
8
Q
Major classes of NHL
A
- indolent (low grade, slow growing) -> folllicular, marginal zone, other
- aggressive (intermediate and high grade, fast growing -> DLBCL, Burkitts, other
9
Q
Indolent NHL
A
- slow growing but often widespread
- typically asymptomatic
- watch and wait strategy
- respond to treatment but relapse
- not considerable curable
- can transform to higher grade lymphoma
10
Q
Aggressive NHL
A
- most often symptomatic at diagnosis
- quite often localised at diagnosis
- progress relatively rapidly without treatment
- death within months to 1-2 years if not treated effectively
- always aggressively treated in fit patients
11
Q
DLBCL
A
- diffuse infiltate of large B cells in node
- patients of all ages
- 50% curable with chemotherapy, those that relapse progress and die of lymphoma
- some relapsong patients can be salvaged with a stem cell transplant usually using the patients own stem cells
12
Q
Burkitt’s lymphoma
A
- aggressive lymphoma with a particular genetic alteration involving a translocation between chromosomes 8 and 14 that justaposes the cmyc oncogene and the iGH gene
- cells have a high mutation rate
- starry sky morphology
- affects all ages and has a predilection to involve the ileum and the NS
- requires aggressive multiagent chemotherapy that can be curative
13
Q
Waldenstroms macroglobulinaemia
A
- indolent lymphoma of lymphoplasmacytoid cells in the BM
- characterised by the morphology and the presence of an IgM paraprotein
- frequently associated with a mutation in the Myd88 signalling pathway protein
- often associated with anemia and splenomegaly
- not treated aggressively as many cases slow to progress
14
Q
Surgical biopsy
A
- cell detail, architecture, flow cytometry, immunohistochemistry and genetics
- required for accurate diagnosis and classification
- gold standard
15
Q
Core biopsy
A
- using ultasound or CT scan is used if excision is difficult
- give limited material and architecture
