Cytology of Lymph Nodes

Question 1

why perform a lymph node cytology

Answer 1

Lymph node enlargement

Suspect metastasis

Question 2

T/F Normal sized lymph nodes are almost always normal

Answer 2

true

Question 3

causes of lymphadenopathy

Answer 3

hyperplasia/antigenic stimulation

lymphadenitis (suppurative, mixed, mononuclear)

metastatic neoplasia

primary neoplasia

Question 4

types of cells seen in lymph nodes

Answer 4

Small lymphocytes

Intermediate-sized lymphocytes

Lymphoblasts

Plasma cells

Macrophages

Eosinophils

Mast cells

Abnormal cells (metastatic neoplastic cells)

Question 5

cell types: hyperplasia/reactive

Answer 5

increased plasma cells

Question 6

cell types: lymphadenitis

Answer 6

neutrophils or macrophages

Question 7

cell types: metastatic neoplasia

Answer 7

clumps of neoplastic cells such as mast cells, epithelial cells, mesenchymal cells

Question 8

T/F in normal lymph nodes small cells predominate

Answer 8

true

Question 9

reactive lymph nodes

Answer 9

enlargement due to proliferation of lymphoid cells

• Predominately small lymphocytes
• Plasma cells increased - KEY to this diagnosis (normal 1-2%)
• lymphoblasts still

Question 10

if you have more that 20% lymphoblasts what do you start to worry about

Answer 10

lymphoma

Question 11

T/F it is uncommon to see the etiology of antigenic stimulation

Answer 11

true

Question 12

T/F cats in early stages of PIV with present with lymphadenopathy

Answer 12

true

Question 13

suppurative lymphadenitis

Answer 13

increased neutrophils

degenerative features depend on the BacT involved

horses-think strangles; Also see in cats with plague

Question 14

T/F specific agents can be identified in lymphadenitis

Answer 14

true

Question 15

lymphoma

Answer 15

Lymph nodes: If > than 50% lymphoblasts, usually >90% not difficult to spot

Question 16

what is a characteristic finding in T cell lymphomas

Answer 16

“Cone heads” - cytoplasmic extensions

Question 17

T/F any malignant tumor can metastasize to L.N.

Answer 17

true

Question 18

T/F cytology is as accurate as histopathology in predicting presence or absence of metastasis in L.N.

Answer 18

true

Question 19

T/F epithelial cells in L.N can be easy to confuse with macrophages

Answer 19

true

Question 20

problems with L.N. cytology

Answer 20

Missed lymph node
   - Perinodal Fat (esp popliteal)
   - Salivary gland
Understained slides
Look for etiologies in reactive nodes, but uncommon to find them

Question 21

what are hematoidin crystals

Answer 21

RBC break down pigment, indicates prior hemorrhage