37 - Pathology of WBCs II Flashcards

1
Q

We have finished B cell…

A

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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe adult T-cell leukemia/lymphoma

A
  • 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 well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does adult T-cell leukemia/lymphoma present?

A

May present with

  • lymphadenopathy
  • skin lesions
  • hepatosplenomegaly
  • lymphocytosis
  • hypercalcemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the properties of adult T-cell leukemia/lymphoma

A
  • 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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the clinical progression and treatment of adult T-cell leukemia/lymphoma

A
  • 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)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the relationship between Mycosis fungoides and Sézary syndrome

A

One disease; two clinical manifestations that overlap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe Mycosis fungoides/Sézary syndrome

A
  • 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)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe mycosis fungoides

A
  • Skin lesions start with premycotic (patch) phase, which has few/a few neoplastic lymphoid cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the two phases of mycosis fungoides?

A
  • Plaque phase

- Tumor phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the plaque phase and the tumor phase of mycosis fungoides

A

Plaque phase
- Few/a few neoplastic lymphoid cells in epidermis***

Tumor phase
- Tumor masses, predominantly in dermis***

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when mycosis fungoides progresses?

A

Disease progresses to involve LN and BM

LN = lymph node
BM = bone marrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe what you see on the skin in the premycotic phase and the tumor phase of Mycosis fungoides/Sézary syndrome

A

Premycotic – a lot of red patches

Tumor phase – tumor cells are mainly in the dermis, making it a protruding mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Sezary Syndrome?

A

Presents with 2 simultaneous manifestations

  • Leukemia
  • Generalized exfoliative erythroderma (peeling of the skin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Now we are moving on to our last section… Immature T cell lymphoid neoplasms (lymphomas)

A

Immature (precursor) T cell neoplasms

  • T lymphoblastic leukemia/lymphoma
  • Anaplastic large T cell lymphoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the clinical presentation of T lymphoblastic leukemia/lymphoma

A
  • 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
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the symptoms of T cell ALL

A

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.

17
Q

What morphology will you see with T cell ALL?

A
  • 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
18
Q

What immunophenotypes will you see in T cell ALL? Which will be negative?

A

KNOW THIS **

Positive

  • CD34, TdT, CD1a (immature markers)
  • Cytoplasmic*** CD3 (surface CD3 negative)
  • Other T cell markers dependent upon stage
19
Q

Describe why CD3 is found in the cytoplasm but not on the cell surface?

A

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
20
Q

What is the prognosis of T cell ALL?

A
  • Unlike B-ALL, most T-ALL are considered higher risk

- More factors relate to poor outcome

21
Q

What factors of T cell ALL predict a poor outcome?

A

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
22
Q

What is the next lymphoma we will study?

A

Anaplastic Large (T) cell Lymphoma (ALCL)

23
Q

What do we call anaplastic Large (T) cell Lymphoma (ALCL)?

A

Non-Hodgkin lymphoma

24
Q

Describe the prevalence of Anaplastic Large (T) cell Lymphoma (ALCL)

A
  • Accounts for 10-20% of childhood lymphomas

- Also found in adults

25
Q

Describe the clinical manefestations of Anaplastic Large (T) cell Lymphoma (ALCL)

A
  • Involves lymph nodes and extranodal sites
  • Mediastinal disease is less frequent than in Hodgkin lymphoma
  • 70% present with stage III-IV disease and (B) meaning they have symptoms
  • This can present as an aggressive lymphoma
26
Q

Describe the significance of the ALK-1 marker in ALCL

A

Anaplastic lymphoma kinase-1

Positive ALK-1

  • Children/young adults
  • Better prognosis, Overall 5 yr survival rate ~80%

Negative ALK-1

  • Especially in elder adults
  • Poor prognosis.

KNOW THIS ***

27
Q

Describe the morphology of ALCL

A

KNOW THIS **

Pleomorphic (variable size and shape) with characteristic “Hallmark” cells

28
Q

Describe the hallmark cells of ALCL (anaplastic large cell lymphoma)

A

Hallmark cells:

(1) medium size
(2) abundant cytoplasm
(3) kidney shaped nuclei,
(4) paranuclear eosinophilic region (pink around nucleus)

29
Q

What are the immunophenotype markers seen in ALCL?

A

KNOW THIS ***

Positive

  • CD30
  • EMA (epithelial membrane antigen)

Negative
- CD3 is negative in 75%

***ALK+/-

30
Q

A 45 year old female presents with palpable mass in her abdomen.
Abdominal CT scan shows retroperitoneal mass and extensive lymphadenopathy and splenomegaly. After lymph node biopsy, the cells are found to be positive for CD10, CD19, CD20 and Bcl-2 by immunohistochemistry. The MOST LIKELY diagnosis is

A.	mantle cell lymphoma.
B.	Burkitt lymphoma.
C.	Sézary syndrome/mycosis fungoides.
D.	follicular lymphoma.
E.	extranodal NK cell lymphoma
A

D. follicular lymphoma.