Lymphadenopathies

Question 1

Where does VDJ rearrangement (somatic recombination) of B cells occur?

Answer 1

BM

Question 2

After somatic hypermutation in BM, B cells go to:

Answer 2

Interfollicular/pericortical areas of lymphatic tissues

Question 3

What three things occur in germinal center?

Answer 3

Antigen presentation, somatic hypermutation, class switching

Question 4

What is Bcl-2?

Answer 4

Anti-apoptotic gene expressed by B cells in germinal centers that are selected to mature

Question 5

What happens to B cell after maturation in germinal center?

Answer 5

Moves out to periphery to be plasma cell or memory B cell

Question 6

Would you expect to find naive B cells in periphery?

Answer 6

Yes, small amount kept just outside mantle zone in marginal zone

Question 7

What presents antigen to B cells in germinal centers?

Answer 7

FDC

Question 8

Where does T cell gene rearrangement occur?

Answer 8

Thymus

Question 9

Where does T cell antigen presentation occur?

Answer 9

Paracortex of lymph nodes/lymphatic tissues

Question 10

What are tingible macrophages? Where are they found?

Answer 10

Macrophages in GC that clean up dead B cells which did not react with antigen/reacted with self antigen

Question 11

Stain lymph node with CD20 mab. Where would you expect to see binding?

Answer 11

GC and mantle zone (B cells)

Question 12

Stain lymph node with CD10 mab. Where would you expect to see binding?

Answer 12

GC (some B cells)

Question 13

Stain lymph node with CD5/3 mab. Where would you expect to see binding?

Answer 13

Paracortex (T cells)

Question 14

Infection or malignancy: Swollen, painful nodes

Answer 14

Infx

Question 15

Infection or malignancy: Swollen node + weight loss + anemia

Answer 15

Malignancy

Question 16

Infection or malignancy: Two nontender, swollen nodes

Answer 16

Malignancy

Question 17

Reactive follicular hyperplasia associated with:

Answer 17

Bacterial infx

Question 18

Paracortical expansion typical of what type of diseases?

Answer 18

Viral infx

Question 19

Two causative agents of infectious mononucleosis:

Answer 19

CMV and EBV

Question 20

Peripheral blood of pt with infectious mononucleosis would look like:

Answer 20

Large mononuclear (no shit) cells with big nuclei

Question 21

What are the large, mononuclear cells seen in PB of infectious mononucleosis? What’s their function?

Answer 21

T cells attacking EBV-infected B cells and pharyngeal epithelial cells

Question 22

Reactive T cells of infectious mononucleosis reside in:

Answer 22

Paracortex

Question 23

Which two cells types would you expect to be most elevated on CBC on pt with infectious mono?

Answer 23

N. segs and lymphocytes

Question 24

Pt with fever, malaise, knots in neck, anorexia, cold sweats, pharyngeal exudate. What test would you order?

Answer 24

Monospot for inf mono

Question 25

As well as causing inf mono, EBV has been implicated in which three other diseases?

Answer 25

Burkitt's Nasopharyngeal carcinoma Lymphomas in immunosuppressed pt

Question 26

Key lymph node finding in patient with SLE?

Answer 26

Lupus lymphadenitis: zones of necrosis (cells' nuclei will no longer stain)

Question 27

Characteristics of dermatopathic lymphadenopathy

Answer 27

Small germinal centers with prominent mantle zones Cells with lots of clear space (cytoplasm) and dark pigments (melanin) = histiocytes

Question 28

What's a histiocyte?

Answer 28

Skin-based macrophage

Question 29

Why do the aggregates of histiocytes in dermatopathic lymphadenopathies have dark pigments in them?

Answer 29

Lymph nodes receive lots of drainage from skin lesions, which contains dead skin cells that contain melanin

Question 30

Three diseases in which you would expect to see aggregates of histiocytes in lymph nodes:

Answer 30

Pemphigus Eczema Psoriasis (any chronic skin disease)

Question 31

Where would one expect to see lymph nodes with histiocytes in pt with dermatopathic lymphadenopathy?

Answer 31

Proximal to the lesion

Question 32

Normal or reactive?

Answer 32

Normal - Normal size and appearance of germinal centers in the cortex, surrounded by a lymph node capsule and adjacent peri-lymph node adipose tissue.

Question 33

Normal or reactive?

Answer 33

Reactive -F ollicular hyperplasia. Multiple large and small follicles with deeply stained mantle zones.

Question 34

Answer 34

Infectious mononucleosis (large, reactive T cells attacking infected B cells and pharyngeal epithelial cells)

Question 35

Burned out follicles

Answer 35

HIV (late phase)

Question 36

Why does late phase HIV cause follicular burn out of lymph nodes?

Answer 36

CD4+ required for normal germinal centers

Question 37

What does lymph node look like in late phase HIV?

Answer 37

No germinal centers Histiocytes replace germinal centers

Question 38

Heterophile Abs

Answer 38

Inf mono

Question 39

What is lymphadenitis?

Answer 39

Increased number of WBCs in lymph nodes, usually due to infx or inflammation