leukemia/lymphoma 4 Flashcards
Mutation responsible for Follicular lymphoma
t(14;18)
BCL2 on 18 translocates to Ig heavy chain locus on chromosome 14
BCL2 stabilizes mitochondrial membrane, inhibiting cytochrome C from leaking into cytoplasm, blocking apoptosis. Thus the process of Somatic Hypermutation is broken and cells don’t die in the follicle.
Lymph node expansion association
Follicles
Paracortex
Sinus histiocytes (in the medulla)
follicles: rheumatoid arthritis and early HIV
paracortex: viral infection (Epstein Barr, Mononucleosis)
Sinus histiocytes: LN draining tissue with cancer
How to tell the difference between follicular lymphoma and hyperplasia
No apoptosis in lymphoma, so there are no macrophages to clear up debris.
Mantle Cell lymphoma mutation
t(11;14)
Cyclin D1 on 11 translocates to Ig heavy chain on 14
Promotes G1/S transition in cell cycle
When is Marginal Zone lymphoma seen?
Most lymph nodes don’t have a marginal zone, but in chronic inflammation states such as
Hashimoto’s, Sjogren syndrome, H pylori gastritis,
the margin is produced.