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.