Pathology of Lymphoproliferative Disorders

Question 1

leukemia defined (contrast to lymphoma)

Answer 1

*blood/bone marrow involvement by neoplastic WBC
*location specific, cell lineage non-specific
*clinical aggressiveness:
-acute = rapid progression, NO cell maturation
-chronic = slowly progressive, cell maturation intact
*hematopoietic cell lineage:
-myeloid = granulocytic / erythroid / megakaryocytic
-lymphoid = B cell or T cell

Question 2

lymphoma defined (contrast to leukemia)

Answer 2

*neoplastic proliferation of lymphocytes at any site (LPD)
*location non-specific, cell lineage “specific”
*clonal lymphoid disorders - malignant neoplastic transformation of lymphocyte or lymphocytic progenitor

note - all lymphomas are malignant, despite the nomenclature

Question 3

Hodgkin Lymphoma - age distribution

Answer 3

bimodal: 2nd to 3rd decades and >6th decades

Question 4

pathogenesis of lymphoproliferative disorders

Answer 4

1. altered immune status (inherited genetic factors, acquired immunodeficiency, autoimmune syndromes, immunosenescence, iatrogenic factors)
2. environmental factors (H. pylori -> gastric MALT lymphoma, etc)
3. lymphotropic viruses (EBV, HTLV-1, HHV-8, HCV)
4. chromosomal translocations (balanced translocations that typically involve activation of oncogenes)

Question 5

B cell antigens

Answer 5

CD10
CD19
CD20
CD79a
sIg (surface immunoglobulin)

Question 6

T cell antigens

Answer 6

CD3
CD4
CD5
CD7
CD8
TCR (T cell receptor)

Question 7

natural killer cell antigens

Answer 7

CD16
CD56