Lymphoid Disorders Flashcards
location of B cell maturation
bone marrow
Immunophenotype of B cells
- CD19, CD20, CD10
Immunophenotype of T cells
- CD3, CD4, CD5
Location of B & T cells w/ in the spleen
- cortex = B cells
- paracortex = T cells
Reactive lymphadenitis/lymphadenopathies morphology
- follicular (nodular)
- sinus
- diffuse
- granulomatous
- necrotizing
- mixed
Reactive lymphoid hyperplasia
- most common in children
- lymph nodes: tender, soft, freely movable
- polarized follicles
- tingible body macrophages, high mitotic activity
- Bcl-2 NEGATIVE in germinal centers*
Infectious Mononucleosis Lymphadenitis
- induced by EBV
- primarily effects adolescents
- REED STERNBERG CELLs
- positive monospot test, EBV-specific antigens
- mixed (diffuse/follicular) lymph node pattern
Cat Scratch lymphadenitits
- contact with cats
- unilateral lymphadenitis
- necrotizing granulomas w/ PMN cells
- positive silver stain
Toxoplasma lyphadenitis
- most common parasitic infection in US
- POSTERIOR CERVICAL lymphadenitis
- fetal toxoplasmosis as a result of transplacental infection possible
- IgM>1:80 is diagnostic
- absence of necrosis
Reactive lymphoid hyperplasia Bcl-2 result
RLH the germinal center cells are Bcl-2 NEGATIVE
Children & young adult lymphoid neoplasia
- hodgkin & burkitt lymphomas
Important clinical features of lymphomas
- enlarge, PAINLESS lymphadenopathy
- B symptoms frequent (fever, chills, NIGHT SWEATS)
Lymphoproliferative disorders
lymphoma & leukemia
Lymphomas
Hodgkin & Non-Hodgkin
Most common lymphomas
- Diffuse large B cell lymphoma: 30.6%
- Follicular lymphoma: 22.1%
Follicular lymphoma
- Adults
- asymptomatic LN enlargement
- back to back follicles
- grade1/2 = 15 centroblasts
- 2/3 of patients present with > Stage III disease*
Follicular lymphoma: immunophenotype
- CD10 & Bcl-2 postitive
- Bcl 2 gene rearragement: t(14;18)
Follicular lymphoma summary
- adults: 6th decade
- lymph nodes: firm, mottled, non movable
- no polarization
- no tingible body marcrophages, low mitotic activity
- Bcl 2 positive germinal centers, t(14;18)