3.25.14* Benign/Reactive Lymphadenopathies and Hematologic Malignancies III Flashcards
PPT 1* Lecture Notes 1* PPT 2* Lecture Notes 2* Pictures (go back and double check last few slides)
anti-apoptotic signaling protein used by B cells?
BCL-2
T cell differentiation occurs in what region of the lymph nodes?
paracortex
B cell differentiation happens in what zone of the lymph nodes?
within follicles of the cortex (aka germinal centers with surrounding mantle zone)
What immunophenotypes are observed in lymph node biopsies to determine B cell and T cell zones?
B cells/ germinal centers: CD20 and CD10
T cells/ paracortex: CD5 or CD3
key clinical finding in reactive lymph nodes?
tender and mobile on palpation. Nodes involved by a malignancy are usually nontender and immobile.
Reactive follicular hyperplasia is associated with
bacterial infection (B cell proliferation)
Cause of paracortical expansion of lymph node?
infectious mononucleosis (viral infection) causing increased T cells and APCs in lymph node -> polymorphic cell population
What is seen in the PBS in patient with infectious mononucleosis?
huge reactive mononuclear cells that are actually activated T cells. These are polymorphic.
What is lupus lymphadenitis?
necrosis of the lymph node
What is seen in dermatopathic lymphadenopathy?
large pale areas in biopsy that are aggregates of histiocytes (tissue-based macrophages) in lymph nodes adjacent to skin lesions in patients with chronic skin diseases (eczema, psoriasis, pemphigus). Dark pigment in histocytes is melanin. This is due to lots of dead skin cells draining to lymph nodes, melanin accumulates in the histiocyte.
HIV lymphadenopathy appearance?
Germinal centers cannot form without CD4 cells. There are mantle zones without germinal centers, but sometimes with histiocytes in the center (which may can activate B cells.)
Immunophenotypes of B cell precursors within the bone marrow
TdT
CD10
(CD19 and CD20 late stage)
Immunophenotypes of B cells after class switching (plasma cells)
CD38
CD138
(CD20-)
Immunophenotypes of naive B cells within lymph nodes?
CD20
CD19
Immunophenotype of B cell undergoing follicular maturation (activated B cell)
CD10
Immunophenotypes of B cells (early to late expression)
Bone marrow a. TdT b. CD10 Naive (mantle and germinal) a. CD20 b. CD19 Germinal center (activated) a. CD10 Perifollicular area (mature plasma cell) a. CD38 b. CD138 (CD20-)
What are the Ig promotors common in B cell malignancies?
IgH
Ig lamda
Ig kappa
Follicular lymphomas/ CLL involve what sites
peripheral blood
bone marrow
lymph nodes
Burkitt lymphoma involves what sites
bone marrow
lymph nodes
GI tract
What type of B cells mutate in CLL?
memory B cells, often found just outside the mantle zone in the lymph node.
Chronic Lymphocytic leukemia/lymphoma
CLL/SLL
a. clinical presentation: high familial incidence.
b. morphology: arise from memory B cells, Small lymphocytes with very little cytoplasm (smudge cells). Increasing presentation of immature lymphocytes
PBS of CLL
lymphocytes are small with scant cytoplasm and mature (dense) chromatin (smudge cells)
lymph node appearance in CLL
pseudofollicular appearance (larger follicular regions that are undergoing DNA synthesis and mitosis)
Genes involved in CLL/SLL
del(13q)
trisomy 12
del (17p) p53, bad prognosis