Multiple Myeloma and MGUS (+some lymphoma) Flashcards
What are lymphomas?
Collection of lymphoid malignancies in which malignant lymphocytes accumulate at LNs and lymphoid tissues; leads to lymphadenopathy, extra nodal disease and constitutional symptoms.
How is Hodgkin distinguished from non-Hodgkin lymphoma?
Presence of Reed Sternberg cells
How are lymphomas staged?
Ann Arbor System (Stage I-IV). Based on LN / extra nodal involvement.
What is the effect and associated neoplasm of t(8;14)?
c-myc activation; Burkitt’s lymphoma.
What is the effect and associated neoplasm of t(14;18)?
bcl-2 activation; Follicular lymphoma
What is the effect and associated neoplasm of t(9;22)?
Philadelphia chr (bcr-abl); CML/ALL in adults (25%)
What is the effect and associated neoplasm of t(11;14)?
Overexertion of cyclin D1 protein.
Mantle cell lymphoma
What is multiple myeloma?
Neoplastic clonal proliferation of plasma cells producing a monoclonal immunoglobulin resulting in end organ dysfunction.
Epidemiology of multiple myeloma?
3/100 000. Most common plasma cell malignancy.
-Increased frequency with age.
Features of end organ damage in multiple myeloma?
CRAB
- Increased Calcium
- Renal failure
- Anemia
- Bony lesions (lytic lesions or osteoporosis felt to be caused by myeloma)
Pathophysiology of multiple myeloma?
Malignant plasma cells secrete monoclonal antibody (95% produce M protein = monoclonal Ig)
Pathogenesis of multiple myeloma?
- Transition of normal plasma cells to precursor disease (monoclonal gammopathy of uncertain significance;MGUS)
- Reflects progression of oncogenic events with acquisition of mutations and cytogenetic abnormalities en route ==> karyotypic instability.
Marrow appearance in multiple myeloma?
Normal marrow
How does the marrow microenvironment facilitate multiple myeloma?
Bone marrow microenvironment promotes proliferation and blocks apoptosis of plasma cells.
- MM cells adhere to ECM proteins of bone marrow through adhesion molecules e.g. VLA4, VCAM1, ICAM1
- Bone marrow homing further facilitated by MM expression of other adhesion molecules e.g. CD138, CD38, CD106
- MM binding induces transcription and secretion of cytokines (e.g. TNFa, IL6, IGF, VEGF), triggering signalling pathways promoting proliferation and preventing apoptosis.
What do normal plasma cells secrete?
Immunoglobulins, composed of heavy chains and light chains. These are polyclonal i.e. different for each plasma cell.