1. MLAB 1315- Hematology Keri Brophy-Martinez
Unit 25: Lymphomas

2. 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. Lymphomas are divided into two major categories: Hodgkin’s and non-Hodgkin’s.

3. Hodgkin’s disease 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

4. Hodgkin’s disease Pathology Characteristic cell is the
Giant size (up to 45µm in diameter)
Abundant acidophilic cytoplasm
Multinucleated or polylobated nucleus
Gigantic nucleoli

5. Hodgkin’s disease: Pathology con’t
Rye Classification determined by lymph node biopsy
Lymphocyte predominance (LP)
Uncommon variety of Hodgkin’s disease
Small, normal-appearing lymphs; benign histiocytes, Rare Reed-Sternberg cell
Mixed-Cellularity
Mixture of lymphs, histiocytes, plasma cells, eosinophils, Reed-Sternberg cells/variants of R-S cells
Lymphocyte-Depletion
Sparse lymphs, predominance of Reed-Sternbergs cells/variants
Many past cases of LD Hodgkin’s may have been misdiagnosed and were really non-Hodgkin’s lymphoma.
Nodular Sclerosing
Sclerosis forms bands of collagen that subdivide the tissue into distinct nodules.
Classic Reed-Sternberg cells
Variant of R-S cell called lacunar cell.

6. Hodgkin’s disease Staging of Hodgkin’s
Stage I - single lymph node region or single organ
Stage II - two or more lymph node regions on the same side of the diaphragm
Stage III - involvement of lymph nodes on both sides of the diaphragm
Stage IV - disseminated into other tissues and organs including bone marrow

7. Hodgkin’s disease 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.

8. 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.

9. Two common lymphomas are:
Burkitt’s lymphoma
Endemic to Africa
1/3 of all non-African pediatric lymphomas
Found in immunocompromised patients, particularly AIDS patients
Tumor 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)

10. Primary cutaneous T-Cell Lymphoma
Infiltration of the skin
Included in this category are mycosis fungoides and Sézary’s syndrome discussed previously.