Lymphoid Disorders

Question 1

Lymphocytes include..

Answer 1

T cells, B cells, natural killer cells

Question 2

What is lymphadenopathy?

Answer 2

Abnormal/enlarged lymph node

Question 3

Where do the T cells commonly reside in the lymph nodes?

Answer 3

T cells usually reside in the interfollicular, paracortex region (space between cortex n medulla)

Question 4

Where do B cells usually reside when in lymph nodes?

Answer 4

B cells usually reside in the 1. secondary lymphoid follicles & in the 2. Medullary cords (plasma cells)

Question 5

What does extranodal lymphoid tissue refer to?

Answer 5

• sites where lymphoid tissue exists other than in lymph nodes

1. Mucosal associated lymphoid tissue
2. Spleen

Question 6

Name some sites of Mucosal associated lymphoid tissue (MALT)

Answer 6

• GIT
• Lungs
• Tonsils

Question 7

How big is a normal lymph node usually?

Answer 7

About 1cm
- anything bigger is abnormal

Question 8

How do you distinguish a whether an abnormal lymph node is benign or malignant?

Answer 8

Benign
1. Tender
2. Discrete
3. Small
4. Mobile, bilateral

Malignant
1. Non-tender
2. Discrete/matted
3. Large
4. Fixed to skin/underlying stuctures

Question 9

What is a very important step when examining an abnormal lymph node?

Answer 9

** regional examination **

Look ard region for
- ulcers
- tumours
- sinuses
- infections

^ all these can give rise to an enlarge lymph node

Question 10

List the benign/reactive causes for an enlarged lymph node

Answer 10

1. Infection
   - bacterial
   - viral e.g. epstein barr virus (infectious mononucleosis
   - granulomatous e.g. mycobacterial, fungal, cat-scratch
2. Immune disorders
   E.g. SLE
3. Drugs e.g. anti-epileptic
4. Unknown etiology e.g. sarcoidosis

Question 11

Name the 2 types of primary lymphomas:

Answer 11

1. Non-hodgkin lymphoma (93%)
- B cell lymphomas
- T & NK cell lymphomas
2. Hodgkin lymphoma (7%)
- classical hodgkin lymphoma
- nodular lymphocyte predominant hodgkin lymphoma

Difference between the 2:
- presence of abnormal cell type: Reed-Sternburg cell => hodgkin

Question 12

Lymphomas are usually primary or secondary?

Answer 12

Secondary/Metastatic lymphomas more common.

• aka cancer spread from elsewhere

Question 13

Granulomas are formed by?

Answer 13

• a discrete collection of epithelial histiocytes
• note: not all granulomas will have multinucleated langhan giant cells!!!

Question 14

What will u see a lot of in an abscess?

Answer 14

Lots of polymorphs and neutrophils

Question 15

How are lymphomas clinically classified?

Answer 15

1. Aggresive vs 2. Indolent
   - though now we use WHO classification

Question 16

What is the difference between aggressive and indolent lymphomas?

Answer 16

Aggresive
- median survival <2y (shorter, poor survival)
- easier to cure, potentially curable
- diffuse large B cell lymphoma, T cell lymphomas
- most childhood lymphomas -> aggressive

Indolent
- median survival >5y (longer survival)
- harder to cure
- follicular lymphoma, marginal zone lymphoma

Question 17

Why is it easier to cure aggressive lymphomas over indolent ones?

Answer 17

• conventional chemotherapy targets actively dividing cells
• aggressive lymphoma grows very fast, thus, cancer cells more susceptible to chemo
• indolent lymphoma cells dont rlly divide, so they are resistant to chemo

Question 18

List the causes of splenomegaly.

Answer 18

1. Infections
2. Congestions (portal hypertension)
3. Lympho-hematogenous disorders/ lympho-reticular diseases
4. Immunologic-inflammatory conditions
5. Storage diseases (rarely due to this)