37 - Pathology of WBCs II Flashcards
We have finished B cell…
Now moving onto T cell lymphomas
Mature (peripheral) lymphoid neoplasms
- T cell lymphomas (adult T-cell leukemia/lymphoma, mycosis fungoides/Sezary syndrome)
Immature (precursor) T cell neoplasms
- T lymphoblastic leukemia/lymphoma
- Anaplastic large T cell lymphoma
Describe adult T-cell leukemia/lymphoma
- MATURE T cell neoplasm ***
- Caused by the HTLV-1 human retrovirus (Human T-cell Leukemia virus type 1)
- Commonly seen in Central Africa, Caribbean, Southwestern Japan
- Long latency period
- 2.5% of Japanese people are carriers
- Occurs ONLY in adults ***
- CD52 is involved in the pathogenesis ***
VERY uncommon in the US (except some cities in FL)
How does adult T-cell leukemia/lymphoma present?
May present with
- lymphadenopathy
- skin lesions
- hepatosplenomegaly
- lymphocytosis
- hypercalcemia
Describe the properties of adult T-cell leukemia/lymphoma
- It is a CD4+ T cell lymphoma ***
- The appearance of cells varies
- You can see immature cells with smooth even chromatin
- You can also see mature, multi-lobulated nuclei called FLOWER CELLS ***
- The HTLV-1 provirus is found in the tumor cell
KNOW ALL THIS
Describe the clinical progression and treatment of adult T-cell leukemia/lymphoma
- Disease is rapidly progressive, death within 1 year despite chemotherapy
- New therapy – anti-CD52 (Alemtuzumab)
- Disease with primarily skin involvement is more indolent (causes little to no pain)
What is the relationship between Mycosis fungoides and Sézary syndrome
One disease; two clinical manifestations that overlap
Describe Mycosis fungoides/Sézary syndrome
- Skin always involved***
- Malignant lymphocytes are CD4+ ***
- Indolent disease (average survival is 8-9 yr )
- Malignant cells have cerebriform nuclei, nuclei with highly folded nuclear membrane ***
KNOW ALL OF THIS
Early on – just red skin, later on – masses on the skin
Cerebriform nuclei (nuclei with highly folded nucearl membrane)
Describe mycosis fungoides
- Skin lesions start with premycotic (patch) phase, which has few/a few neoplastic lymphoid cells
What are the two phases of mycosis fungoides?
- Plaque phase
- Tumor phase
Describe the plaque phase and the tumor phase of mycosis fungoides
Plaque phase
- Few/a few neoplastic lymphoid cells in epidermis***
Tumor phase
- Tumor masses, predominantly in dermis***
What happens when mycosis fungoides progresses?
Disease progresses to involve LN and BM
LN = lymph node BM = bone marrow
Describe what you see on the skin in the premycotic phase and the tumor phase of Mycosis fungoides/Sézary syndrome
Premycotic – a lot of red patches
Tumor phase – tumor cells are mainly in the dermis, making it a protruding mass
What is Sezary Syndrome?
Presents with 2 simultaneous manifestations
- Leukemia
- Generalized exfoliative erythroderma (peeling of the skin)
Now we are moving on to our last section… Immature T cell lymphoid neoplasms (lymphomas)
Immature (precursor) T cell neoplasms
- T lymphoblastic leukemia/lymphoma
- Anaplastic large T cell lymphoma
Describe the clinical presentation of T lymphoblastic leukemia/lymphoma
- Medical emergency
- 85% presents as a mass (lymphoma)
- Mass is typically located in the anterior mediastinum or cervical lymph nodes
- 15% present as leukemia (ALL= acute lymphocytic leukemia)
- The symptoms of the T-cell ALL is similar to B-cell ALL
Describe the symptoms of T cell ALL
ALL = Acute lymphocytic leukemia
- Abrupt stormy onset: within days to few weeks of symptoms
- Depression of normal marrow: fatigue due to anemia, infection, bleeding secondary to thrombocytopenia (low platelets b/c bone marrow is involved).
- Mediastinal mass, Lymphadenopathy, splenomegaly, hepatomegaly due to neoplastic infiltration.
CNS INVOLVEMENT***
- headache, vomiting, nerve palsies due to meningeal spread.
What morphology will you see with T cell ALL?
- Monotonous population of blasts (all look the same)
- May have more clumped chromatin
This is described as a “sheet of blasts” ****
- Found in lymph node, soft tissue or bone marrow
- When you see this, think T cell ALL
What immunophenotypes will you see in T cell ALL? Which will be negative?
KNOW THIS **
Positive
- CD34, TdT, CD1a (immature markers)
- Cytoplasmic*** CD3 (surface CD3 negative)
- Other T cell markers dependent upon stage
Describe why CD3 is found in the cytoplasm but not on the cell surface?
Cytoplasmic CD3 positive, surface CD3 negative
- NOT found on the surface of mature T cell
- The CD3 was produced by the cytoplasm, but they have not matured enough to be found on the surface
What is the prognosis of T cell ALL?
- Unlike B-ALL, most T-ALL are considered higher risk
- More factors relate to poor outcome
What factors of T cell ALL predict a poor outcome?
Factors that predict poor outcome
- Age under 2
- Presentation in adolescence or adulthood
- Presence of Philadelphia chromosome t(9;22) or translocation involving the MLL gene on ch 11
- ** If this is positive, prognosis is NOT good
- WBC > 100,000
What is the next lymphoma we will study?
Anaplastic Large (T) cell Lymphoma (ALCL)
What do we call anaplastic Large (T) cell Lymphoma (ALCL)?
Non-Hodgkin lymphoma
Describe the prevalence of Anaplastic Large (T) cell Lymphoma (ALCL)
- Accounts for 10-20% of childhood lymphomas
- Also found in adults
