Diseases of the myeloid and lymphoid system

Question 1

What does myeloid mean

Answer 1

derived from bone marrow

Question 2

what does lymphoid mean

Answer 2

derived from lymph tissue

Question 3

what is lymphoma

Answer 3

cancer of the lymph nodes or lymph tissue

Question 4

List some myeloid cells

Answer 4

neutrophils
basophils
eosinophils
monocytes
macrophages
erythrocytes
thrombocytes

Question 5

list the lymphoid cells

Answer 5

lymphocytes

Question 6

List 6 common stimuli that can trigger the immune system

Answer 6

physiologic leukocytosis - fight or flight
physiologic stress
iatrogenic antigenic stimulation - vaccines
inflammation
infection
parasites/ FBs

Question 7

describe the stress leukogram cell response

Answer 7

neutrophilia
lymphopaenia
monocytosis
eosinopaenia

Question 8

in what condition will you not see a stress leukogram in dogs

Answer 8

Addisions disease

Question 9

why do you not see stress leukograms in Addison’s

Answer 9

insufficient cortisol is being produced to stimulate a stress response

Question 10

what is reactive hyperlapsia

Answer 10

LN enlarges as part of the immune response to lymphatic drainage from an affected site

Question 11

what is the most useful method for assessing a lymph node

Answer 11

FNA

Question 12

why are inconclusive results common on FNA of submandibular LNs

Answer 12

because you can very easily hit the salivary glands

Question 13

what is chyle

Answer 13

mix of lymph and chylomicrons

Question 14

what are chylomicrons

Answer 14

lipids absorbed from intestine and transported via lymphatics

Question 15

List 3 ways in which chylous effusions can occur

Answer 15

rupture - trauma
obstruction of thoracic duct or other major lymphatic vessel
often idiopathic - site of leak not always determined

Question 16

what is the most common treatment of a chylothorax and chyloabdomen

Answer 16

surgical closure of the thoracic duct

Question 17

what is lymphangiectasia

Answer 17

dilation of intestinal lymphatics and subsequent loss of chyle into the lumen

Question 18

List the ways in which lymphagiectasia can occur

Answer 18

idiopathic
congenital
acuired obstruction (neoplasia)

Question 19

how can lymphangiectasia lead to Protein losing enteropathy

Answer 19

chyle is lost into the lumen of the intestines and this leads to a loss of proteins

Question 20

how can lymphangiectasia be managed

Answer 20

low- fat diet +/- immunosuppressives (e.g. prenisolone)

Question 21

how can we investigate lymphangiectasia

Answer 21

the best way is via intestinal biopsy

Question 22

why is endoscopic biopsy better than surgical biopsy in cases of lymphangiectasia

Answer 22

low albumin is associated with a risk of wound dehiscence - this makes surgical biopsies prone to complications

Question 23

what would you see on biochem and haematology in lymphangiectasia cases

Answer 23

hypocholesterolaemia
hypoalbuminaemia
lymphopaenia

Question 24

what might we need in order to diagnose a myeloid disease

Answer 24

bone marrow aspirates

Question 25

what is aplastic anaemia

Answer 25

failure of bone marrow to produce enough cells - low RBCs, WBCs and platelets

Question 26

List 3 non-neoplastic things that can cause aplastic anaemia

Answer 26

toxicity adverse drug reactions infections

Question 27

what is the first cell that will decrease in numbers in aplastic anaemia

Answer 27

neutrophils, shortly followed by platelets

Question 28

what is myeloid leukaemia

Answer 28

myeloid stem cells become cancerous

Question 29

what is polycythaemia vera

Answer 29

An excess of red blood cells in the circulation - due to myeloid leukaemia

Question 30

List 3 neoplasias of myeloid cell origin

Answer 30

mast cell tumour histiocytoma transmissible venereal tumour

Question 31

what cells are involved in histiocytomas

Answer 31

macrophages

Question 32

are histiocytomas usualy malignant or benign

Answer 32

benign

Question 33

why must you be careful when diagnosing a histiocytoma and advising owners to leave it

Answer 33

it could possibly be a mast cell tumour

Question 34

list 5 breeds that are prone to mast cell tumours

Answer 34

BOXERS labradors golden retrievers Staffies boston terriers pugs

Question 35

List 3 things thta make mast cell tumours very bad

Answer 35

variability of grades locally invasive risk of degranulation

Question 36

what does a high grade Mast cell tumour mean

Answer 36

it may spread to lymph nodes, liver, spleen or bone marrow

Question 37

what margins do you need to take for high grade Mast cell tumours

Answer 37

3 cm margins and 1-2 fascial planes deep

Question 38

what do we mean by an MCTs risk of degranulation

Answer 38

mass histamine release can lead to anaphylaxis - this mass release can occur due to handling

Question 39

what do we need in order to grade an MCT

Answer 39

histopathology

Question 40

what characterises a MCT as high grade

Answer 40

High mitotic index multinucleated cells atypical nuceli ansiokaryosis - cells varialy shaped

Question 41

Decsribe how mast cell tumours are treated

Answer 41

surgery can do chemotherapy, palliative care or alongside surgery

Question 42

what are tyrosine kinase inhibitors

Answer 42

inhibit TK - a protein involved in cellular proliferation

Question 43

List 2 types of feline mast cell tumours

Answer 43

cutaneous form visceral form

Question 44

what is a plasmacytoma

Answer 44

tumour of plasma cells

Question 45

what are the 2 types of lymphoma

Answer 45

B-cell T-cell

Question 46

what type of lymphoma may be able to be surgically resected

Answer 46

T zone 'indolent' lymphoma - only present in one lymph node

Question 47

what can be the consequence of insufficient neutrophils

Answer 47

the animal will be very susceptible to infection

Question 48

how is transmissible venereal tumour spread

Answer 48

during mating

Question 49

can transmissible venereal tumours be treated

Answer 49

yes with chemotherapy