Cytology Eval Lymph Tissue - Ex 6

Question 1

6 pathological processes assoc’d with LN’s

Answer 1

1. Hyperplastic
2. Reactive
3. Edematous
4. Inflammatory
5. Lymphoma
6. Metastatic neoplasia

Question 2

What two LN sites are preferred?

Answer 2

Popliteal and pre scapular

Question 3

Which LN is hard to obtain sample from?

Answer 3

submandibular

Question 4

Why should you avoid extremely enlarged LNs?

Answer 4

Middle may be necrotic –> unable to dx

Question 5

LN Aspiration gone wrong (3)

Answer 5

1. Perinodal fat
2. Salivary tissue
3. Cell lysis

Question 6

Normal/Hyperplastic

Answer 6

• 75-95% small, well-differentiated lymphocytes
• 1-1.5x the size of RBC
• Low numbers of int. and lg. lymphocytes
• Occasional histiocytes (MOs)
• rare plasma cells & mast cells

Question 7

Reactive

Answer 7

MOST COMMON!!

• Small, well-differentiated lymphocytes predominate
• Inc numbers of int. & lg. lymphocytes
• Increased number of PLASMA CELLS (with golgi zone)
• Low numbers of Mott cells
• Slightly increased numbers of neutrophils and MOs
• Low numbers of mast cells

Question 8

Reactive Lymphoid Tissue

Answer 8

Reactivity is usually due to Ag stimulation of draining areas
- infection, inflammation, neoplasia, etc

Question 9

If several lymph nodes are reactive, what should we be thinking?

Answer 9

Systemic disease!

1. Systemic infection
   - fungal, rickettsial, bacterial, viral, etc
2. Autoimmune dz
   - SLE, polyarthritis, polymyositis, etc

Question 10

Distinctive peripheral LN hyperplasia (idiopathic lymphadenopathy)

Answer 10

occurs in cats 2-4 yrs old

Looks like multicentric lymphoma

Peripheral lymphadenopathy regresses in 1-17 weeks

May be assoc’d with underlying infection
- e.g. FeLV

Question 11

Lymphedema

Answer 11

Usually caused by obstruction of lymphatics

• Clear to slightly cloudy fluid seen during aspiration
• Low numbers of cells
• Small, well-differentiated lymphocytes predominate
• Plasma cells are frequently observed

Question 12

Lymphadenitis - 3 kinds

Answer 12

1. Purulent (suppurative) lymphadenitis
   * Neutrophilic inflammation
   - usually bacterial infection
2. Granulomatous or pyogranulomatous inflammation
   *high numbers of MO & +/- neutrophils
   (think fungi, parasites, infectious agents, etc)
3. Eosinophilic
   * Increased eosinophils with some neuts & MO
   - Allergic dermatitis (COMMON in dogs)
   - others (parasites, hypersensitivity, etc)

Question 13

Lymphoma

Answer 13

Common in dogs

Lymphoblasts predominate

Lymphoglandular bodies are common
- pieces of cytoplasm

Increased numbers of mitotic figures may be seen

Question 14

What should we suspect if >30% of the cells are lymphoblasts?

Answer 14

Lymphoma

Question 15

When can we dx lymphoma?

Answer 15

If >50% of cells are lymphoblasts

Question 16

Lymphoma Tx

Answer 16

Glucocorticoids - they may lyse lymphoblasts & decrease the percentage observed

Question 17

Immunological typing - lymphomas

Answer 17

most accurate way to determine cell type involved (B, T, NK cells, etc)

Question 18

Metastatic Dz

Answer 18

These look angry!

• Homogenous pop of cells not normally present in a lymph node are seen
• Reactivity is often seen in LN draining the tumor AND in LN w/metastatic lesions

–metastasis may be present even if the LN is not enlarged AND even if the anapestic cells are not seen during cytologic evaluation