Hodgkin Lymphoma Flashcards
(44 cards)
what is Hodgkin Lymphoma?
it’s a unique form of B-cell lymphoma with an excellent prognosis. Cells have largely lost their B-cell phenotype.
HL arises from lymphoid tissue
Reed-Sternberg cells are characteristic to an HL lymph node biopsy
what are Reed-Sternberg cells?
characteristic to an HL - this cell is not found in other types of lymphoma
***when present, true RS cells are diagnostic of HL
a binucleated cell with centrally located nucleoli giving it a classic “owl’s eye” appearance
go look at a picture of it
what type of cell do RS cells originate from?
germinal or post-germinal B cells
what immunophenotype markers are RS cells positive for?
CD15 and CD30
they don’t stain positive for CD 20! this weird loss of the B-cell phenotype makes HL unique among other lymphomas
what does an H&E of HL show?
a reactive cell population – the reactive cell population makes up the bulk of the “tumor,” even though the reactive cells are totally benign
lymphocytes are most commonly found but eosinophils may also be present
RS cells and their variants only make up a small percentage of the total number of cells present
what are the 5 histological subtypes of HL?
- nodular sclerosis
- mixed cellularity
- lymphocyte-rich
- lymphocyte-depletion
- lymphocyte-predominance HL (not a classic subtype)
what is nodular sclerosis HL?
Classic RS cells or lacunar cells (CD15+, CD30+ immunophenotype)
lacunar cells are variant RS cells
fibrous bands divide the lymph nodes into nodules
presents with cervical, supraclavicular or mediastinal lymphadenopathy
good prognosis!
what population in nodular sclerosis HL most common in and what’s its overall prevalence?
60% prevalence
M=F
more common in adolescents and young adults
what is mixed cellularity HL?
there’s an abundant background infiltrate of all different kinds of cells like eosinophils, lymphocytes, plasma cells, macrophages
these cells are recruited by IL-5 which is secreted by the RS in this subtype of HL
systemic involvement
over half of the patients with this subtype present with advanced-stage disease, but the prognosis overall is still good
what population in mixed cellularity HL most common in and what’s its overall prevalence?
25% prevalence
M>F
biphasic incidence, with one peak in young adulthood and another in adults over the age of 55
what is lymphocyte-rich HL?
has classic RS cells
has lymphocytes form background inflammatory infiltrate
present with early-stage localized lymphadenopathy and has a great prognosis!
B symptoms are rare
what’s lymphocyte-rich HL overall prevalence?
5% prevalence
what is lymphocyte-depletion HL?
CD15+, CD 30+ RS cells
few inflammatory cells in the background
necrosis and fibrosis present
more aggressive; systemic symptoms common
usually presents with advanced stage disease and prognosis is less favorable.
what is the prevalence of lymphocyte-depletion HL?
5%
what is lymphocyte-predominance HL?
classic RS cells are rare; instead there’s multilobed CD20+ “popcorn cell
tons of small B-cells and macrophages in histology
usually limited to cervical or axillary lymphadenopathy
B symptoms are rare
relapsing course; good prognosis!
what’s the prevalence of lymphocyte-predominance HL?
5%
what’s the most common type of HL?
nodular sclerosis
what are lacunar cells?
variant RS cells present in nodular sclerosis HL
lacunar cells have delicate nuclei that appear to sit in clear “lakes” (lacunae)
this is because formalin fixation of the tissue causes the cell cytoplasm to retract, leaving an empty space around the nucleus of the cell
what’s the immunophenotype of lacunar cells?
CD15+, CD30+
the exact same as classic RS cells!
what’s the least common type of HL?
lymphocyte-depletion HL
what population in lymphocyte-deletion HL most common in?
typically occurs in older adults and in HIV positive patients
what population is lymphocyte predominance HL most common?
usually males under 35 years old
what makes lymphocyte-predominance hL a separate entity from classical HL?
- classic RS cells are scare
there are neoplastic B cells that express J chains, epithelial membrane antigen (EMA), CD 20, and CD 45 on their cell surface – classic RS cells have CD15 and CD30 on its surface
- lymphocyte- predominance HL has its very own malignant cells, often referred to as the popcorn cell
they express CD20 and are variant RS cells
Which neoplastic cells are present in lymphocyte-predominance HL and which markers do they express?
Lymph node biopsy in lymphocyte-predominance HL shows proliferating B cells that express J chains, epithelial membrane antigen, CD 20 and CD 45 on their cell surface.
macrophages are also usually present. Another type of malignant cell found in in this subtype is the so-called CD20+ popcorn cell, which is a variant of the classic RS cell.
