MLAB 1415: HEMATOLOGYKERI BROPHY-MARTINEZChapter 26: Lymphoid Malignancies
Part Two
LYMPHOMAS
These are a heterogeneous group of diseases that arise from an overproliferation of abnormal cells of the lympoid tissue (lymphocytes, histiocytes, and reticulum cells). The spilling of these cells into the peripheral blood results in a leukemic phase of the disease.
DIVISION OF LYMPHOMAS: HODGKIN’S AND NON-HODGKIN’S
Parameter Hodgkin Lymphoma
Non-HodgkinLymphoma
Stage localized widespread
Distribution Central nodes Peripheral nodes
Mode of spread Close Not close
Extranodal disease Uncommon common
Peripheral blood Never involved Can be involved
Cell type Abnormal bizarre cells
Resembles normal lymphoid cells
HODGKIN’S LYMPHOMA
Etiology and clinical features Probable cause is Epstein-Barr virus. Diagnosed between 15 and 35 years of age; also
found in over 50 population Nonpainful lymph node swelling
HODGKIN’S LYMPHOMA
Pathology Characteristic cell is the Reed-Sternberg
Giant size (up to 45µm in diameter) Abundant acidophilic cytoplasm Multinucleated or polylobated nucleus Gigantic nucleoli
HODGKIN’S LYMPHOMA
Staging of Hodgkin’sStage I - single lymph node region or
single organStage II - two or more lymph node regions
on the same side of the diaphragmStage III - involvement of lymph nodes on
both sides of the diaphragmStage IV - disseminated into other tissues
and organs including bone marrow
HODGKIN’S LYMPHOMA
Treatment and prognosis Radiation of localized involvement Chemotherapy Combination of above With early diagnosis, long-term disease-free
survival is seen in about 75% of cases.
NON-HODGKIN’S LYMPHOMA
Cause is unknown at this time. Predisposing factors seem to be chemicals, ionizing radiation and certain viruses. Reed-Sternberg cells are NOT present.
The types of non- Hodgkin’s lymphoma reflect the developmental stages of lymphocytes.
Each type of lymphoma can be viewed as a lymphocyte arrested at a certain stage of development and transformed into a malignant cell.
85% B cell origin, the rest T or null cell.
BURKITT LYMPHOMAEndemic to Africa1/3 of all non-African pediatric lymphomasFound in immunocompromised patients,
particularly AIDS patientsTumor growth rate is the highest of any
tumor with growth doubling each day.Rapid growth and tumor cell death results in
“starry sky” appearance of the biopsy caused by macrophages cleaning up the dead cells.
Characteristic overgrowth of facial bones in the African variety and abdominal mass in the non-endemic variety.
Cytogenetic translocation t(8:14)
BURKITT LYMPHOMA
•Overgrowth of facial bones
PLASMA CELL DISORDERS
• Disorders that do not involve lymph nodes • Secrete monoclonal immunoglobulin into the
serum and /or urine• Disorders
• Multiple Myeloma• Plasmacytoma• Primary amloidosis• Heavy Chain disease• Monoclonal gammopathy of undetermined
significance
MULTIPLE MYELOMA
This is a disorder in which there is overproduction of abnormal plasma cells which are the final stage in the development of B lymphocytes.
ETIOLOGY
50% greater risk for men than women Risk increases with age; rare under 40
Median age 65 years old
Suspected cause is chronic stimulation of the immune system from environmental sources. Ionizing radiation Viruses
FEATURES
Expanding plasma cell mass in bone marrow causes pancytopenia and destruction of the bone cortex. This is painful because nerves get stretched.
Formation of tumors causes lytic bone lesions
Bone lesions
FEATURES Increased production of immunoglobulin heavy and
light chains (monoclonal gammopathy) Heavy chains: IgG, IgA, IgD, IgE, IgM Light chains: kappa, lambda Most common type of multiple myeloma is increased
production of IgG.
Hyperviscosity syndrome Excess immunoglobulin causes viscous blood which
sludges and causes fluid congestion.
Bence-Jones protein Light chains spill into the urine and can be detected by
lab test. Causes kidney damage
LAB FINDINGS
CBC and peripheral smear Red cells form characteristic rouleaux formation (resemble
stacked coins) Plasma cells may be seen in advanced cases The presence of significant numbers of plasma cells on
peripheral blood smear constitutes plasma cell leukemia
ESR Increased - serum protein causes red cells to stick together and
fall faster Bone marrow
Increased number of plasma cells which form “sheets” Chemistry studies
Increased BUN and creatinine (kidney tests) Increased calcium Increased LDH
MULTIPLE MYELOMA
MULTIPLE MYELOMA
Treatment Chemotherapy Radiation for localized areas Bone marrow transplant for younger patients
WALDENSTRÖM’S MACROGLOBULINEMIA
Overproduction of monoclonal IgM by plasma cells
Clinical features Usually presents when patients are in their 70's. Hyperviscosity syndrome is common. Blurred vision IgM interferes with platelet function and bleeding
problems occur. Characteristic bruising is called cryoglobulinemic purpura
Cryoglobulins precipitate on exposure to cold
REFERENCES
http://www.itriagehealth.com/wl/disease/burkitt-lymphoma-%28lymph-node-tumor%29#wrapperTop
McKenzie, S. B., & Williams, J. L. (2010). Clinical Laboratory Hematology . Upper Saddle River: Pearson Education, Inc.