Lymphoid Neoplasms Flashcards
Is lymphoma a common malignancy?
Yes - 6th most commonly diagnosed cancer
How should lymph nodes be sent to the pathology lab for testing?
Fresh, with no formalin or other fluids in tub
Where are T cells made?
Bone marrow
Where do T cells mature?
Thymus
Where do T cells become activated?
Secondary lymphoid organs
Where are B cells made?
Bone marrow
Where do B cells mature?
Bone marrow
Lymphoid organs
Where do B cells become activated?
Lymphoid follicles
Paracortex
Where does the lymph enter a lymph node?
Afferent lymphatic vessel > marginal sinus
Where are the follicles and germinal centres located in the lymph node?
In cortex
Where do T cell responses occur in the lymph node?
Paracortex
Medulla
What is contained within the medulla of the lymph node?
T cells
Medullary sinuses
What is the translocation in Burkitt lymphoma?
t(8;14)
How is the t(8;14) translocation involved in the pathogenesis of Burkitt lymphoma?
c-MYC gene on chromosome 8 translocated to Ig gene on chromosome 14
What is the translocation in follicular lymphoma?
t(14;18)
How is the t(14;18) translocation involved in the pathogenesis of follicular lymphoma?
Heavy chain locus on chromosome 14 translocated to Bcl-2 locus on chromosome 18 > increased expression of Bcl-2 > increased anti-apoptotic activity
Wat are the characteristic cells seen in Hodgkin’s lymphoma?
Reed-Sternberg cells
What methods can be used to identify the CD antigens on cells?
Immunohistochemistry
Flow cytometry
In situ hybridisation
What investigations can be used to confirm that a monoclonal population of cells is present?
All molecular techniques based on clonal proliferation
- PCR
- FISH
- Immunohistochemistry
- Flow cytometry
What does immunohistochemistry identify?
Panel of Ag markers to detect surface markers and other proteins
Detect EBV DNA
Can correlate with histology
What does flow cytometry identify?
Analysis of fluorochrome labelled cells
Detects surface markers for immunophenotyping
Detects B cell clonality
No correlation with histology
What does PCR identify?
Assesses monoclonality by assessing IgH gene/T cell receptor gene rearrangements
Identify specific translocations
What does FISH identify?
Specific translocations and other genetic abnormalities
A blood smear showed increased numbers of small mature lymphocytes. In the context of haematological malignancies, what is the likely diagnosis?
Chronic lymphocytic leukaemia
What test would be needed to confirm the diagnosis of chronic lymphocytic leukaemia?
FBE
Liver/spleen ultrasound
Bone marrow biopsy
What is the likely cause of lymphadenopathy and splenomegaly in the context of haematological malignancies?
Malignant infiltrate
What is CD19 a marker of?
B cells
What is CD10 a marker of?
Follicular lymphoma
What are the management options for someone with chronic lymphocytic leukaemia?
Monitor
Treatment
- Chemotherapy
- Immunotherapy
What is rituximab?
mAb against CD20
What is ZAP-70 and what is its relevance in chronic lymphocytic leukaemia?
If present, poor prognosis in CLL
What is Richter’s transformation?
Transformation of small cell lymphomas/CLL into diffuse large B cell lymphoma
What are the symptoms of superior vena cava syndrome?
Headache Facial oedema Facial congestion Shortness of breath Distended veins in upper limbs and neck
What causes superior vena cava syndrome?
Compression of superior vena cava
How much of the lymph node can be neoplastic in Hodgkin’s lymphoma?
Up to 5%
What is the pathogenesis of Hodgkin’s lymphoma?
Clonal proliferation of B cells of germinal centre origin
Produce cytokines > attract other inflammatory cells
EBV present in 40-80%
Other genetic risk factors
What are some examples of EBV related diseases?
Infectious mononucleosis
Lymphoproliferative disorders
Nasopharyngeal carcinoma
What are some lymphoproliferative disorders related to EBV?
Burkitt lymphoma Plasmablastic lymphoma DLBCL Haemophagocytic lymphohistiocytosis Post-transplant lymphoproliferative disorder
What are the risk factors for lymphoma?
Many arise de novo Immunosuppression/immunodeficiency Some autoimmune diseases EBV H pylori Other infectious agents Chemotherapy Radiation Chemical exposure
What is the usual site of non-Hodgkin’s lymphomas?
Usually arise in lymphoid organs
Many extranodal; eg:
- Thyroid in Hashimoto’s disease
- Stomach in H pylori gastritis
What is the usual site of Hodgkin’s lymphomas?
Initially enlargement of 1 lymph node group
May progress to involve adjacent lymph node groups and other lymphoid organs
What are the systemic symptoms of lymphoma?
Fever
Weight loss
Night sweats
A 65-year-old man presents with a several month history of generalised lymphadenopathy. A lymph node biopsy demonstrates effacement of normal architecture which is replaced by nodular proliferations of predominantly small cleaved lymphocytes resembling germinal centre B cells. A (14;18) translocation in the malignant cells is identified. What is the lymphoma?
Burkitt lymphoma
A 24-year-old female presented with a 6 week history of fever, weight loss, shortness of breath, and cervical lymphadenopathy. Two months earlier she had spent 2 weeks in Vietnam. Chest x-ray revealed an anterior mediastinal mass. Reed-Sternberg cells are seen in the biopsy. What is the diagnosis?
Hodgkin lymphoma
