Hodgkin and Non Hodgkin Lymphoma; CLL and plasma cell disorders Flashcards
- Describe the basic anatomy of a normal lymph node and the common abnormal lymph node patterns seen in lymphomas
Normal lymph node: Circulation: -Afferent lymphatic vessels -Efferent lymphatic vessels -Blood supply via artery and vein
Parenchyma:
-Surrounded by thin and fibrous capsule
-Cortex contains primary and secondary lymphoid follicles (mostly B cells) and Paracortex (mostly T cells)
Lymphoid follicles contain an outer mantle zone (all B-cells, uniform, tightly packed), and a germinal center consisting of a light zone (mixed B-cells, T cells, macrophages) and dark zone (Mostly B cells)
-Medulla: contains medulla cord and medulla sinus
Define lymphadenopathy and list the common disease categories associated with lymphadenopathy.
Lymph nodes that are abnormal in size, number, or consistency.
Associated with CLL/SLL, Follicular lymphoma, and Mantle cell lymphoma.
Explain the basic principles for the WHO Classification of lymphomas.
Morphology, immunophenotype, genetic findings, location, age
CLL/Small lymph lymphoma:
cytology:small and monotnous size, round nuclei, w/ condensed chromatin, inconspicuous nucleoi, scant granular cytoplasm, frequen smudge cells and basket cells,
Immunophenotype:
Positive: CD5, CD19, CD23
Weakly positive: CD20
Negative: CD10, FMC7
genotype: del(13q14) most common
trisomy chromsome 12
deltion of 11q22-q23
deletion of 17p13
Follicular Lymphoma
Cytology: germinal center, B cell origin
Two types of tumor cells:
centerocytes: small to medium size with scan cytoplasm; angulated, twisted nuclei, inconspicuous nucleoli
Centroblasts: large transformed cells with round or oval nuclei and vesicular chromatin; narrow rim of cytoplasm, 1-3 peripheral nucleoli
Immunophenotype:
Cd19+, CD20+, BCL2+, CD10+ BCL6+
genotype: t(14;18)(q32;q21), places BCL2 oncogene of chromosome 18 under control og IGH promoter on chromosome 14—-> induces MASSIVE FOLLICULAR LYMPHOID HYPERPLASIA
Mantle Cell Lymphoma (MCL)
Cytology: small to medium size, slightly larger than normal lymphocytes, slightly irregular nuclear contours, resembling centrocytes but often have slightly less irregular contours
Immunophenotype: CD19+, CD20+ CD5+ CD23-, BCL1 positive (cyclin D1), CD10+ BCL6+
Genotype: t(11;14)(q13;q32), involving BCL1 gene on 11q13 and IGH gene on 14q32
Burkitt’s Lymphoma (BL)
Cytology: Diffuse infiltration of monomorphic, medium-sized cells with starry sky pattern, tumor cells have abundant basophilic cytoplasm, round nuclei, intracytoplasmic lipid vacuoles.
Immunophenotype: CD19+, CD20+, BCL2-, CD5-, CD23-, TdT-
Genotype: Most cases have a characteristic translocation, t(8;14)(q24;q32), which juxtaposes the MYC gene at 8q24 next to IGH@ at 14q32
Define indolent, aggressive and highly aggressive as these terms relate to lymphoma. Be familiar with some common types of indolent and aggressive lymphomas.
Indolent: Slow to develop
Agressive: develops faster
Highly aggressive: develops and spreads very fast
List and describe the common types of lymphoma in adults and children.
Children: Burkitt’s lymphoma, Mixed cellularity variant of classical Hodgkin’s lymphoma
Adults: Follicular Lymphoma, Nodular Sclerosis CHL in young adults
Explain the importance of rearrangements involving the BCL2, BCL1 and MYC genes in the pathogenesis of lymphoma.
BCL2 promotes massive follicular lymphoid hyperplasia when activated by IGH promoter
BCL1 leads to a constant over expression of Cyclin D1, leading to neoplasm and tumor development in Mantle cell lymphoma.
Translocations of MYC oncogene are a constant feature of Burkitt’s lymphoma.
List and describe the major subtypes of classical Hodgkin lymphoma (CHL).
Nodular sclerosis CHL:
- most frequent, 50-80% of all CHLs
- predominates in young adult women
- typically occurs above diaphragm
- thickened lymph node capsule w/ broad bands of collage
Mixed cellularity CHL
