Cell Accumulations

Question 1

Appearance of hepatic lipidosis

Answer 1

Grossly: enlarged/yellow liver

Histologically: hepatocytes contain “empty” vacuoles that displace the nucleus and can be stained by Sudan black

Question 2

True or false: hepatic lipidosis occurs only in obese animals.

Answer 2

False. Malnourishment can cause defective oxidation of FAs or apoprotein synthesis

Question 3

Cause and signs of feline hepatic lipidosis

Answer 3

Anorexia (in obese cats) -> Mobilization of fat stores -> Lipid processing overwhelmed

Elevated bilirubin -> icterus of ear

Question 4

How does pregnancy toxemia (sheep, goats, and cattle) lead to hepatic lipidosis?

Answer 4

1. Late pregnancy in over conditioned animals
2. Inadequate nutrition
3. Low propionic acid -> hypoglycemia
4. Fat/glycerol metabolized.oxidized to Acetyl-CoA
5. Ketoacidosis (due to excess acetyl-CoA)

Question 5

Glycogen storage disease is secondary to which two diseases?

Answer 5

1) Canine hyperadrenocorticism
- Glucocorticoids induce glycogen synthetase
- AKA canine steroid (vacuolar) hepatopathy

2) Diabetes mellitus
- Hyperglycemia - glycogen accumulation in hepatocytes, renal tubules, pancreatic islet (beta) cells

Question 6

Reabsorption droplets

Answer 6

• Eosinophilic drops in renal tubules
• Caused by protein load > glomerular filtration capacity
• Intestinal hyaline droplets = normal in neonates

Question 7

Russell bodies

Answer 7

• Caused by XS immunoglobulins made by plasma cells
• i.e. multiple myeloma (plasma cell cancer) or chronic inflammatory conditions [chronic inflammation = plasma cells; neutrophils mediate immediate inflammation]
• little unstained circles in plasma cell

Question 8

Name 4 examples of prion diseases

Answer 8

1) Scrapie (sheep)
2) Bovine spongiform encephalopathy
3) Chronic wasting disease (deer/elk)
4) Creutzfeldt-Jacob disease & Kuru (people)

Question 9

Which geometry enables prions and amyloids to resist proteases?

Answer 9

Beta-pleated sheets

Question 10

Carbon/dust

Answer 10

• Most common exogenous pigment

- carried to LN by macrophages

Question 11

Anthracosis

Answer 11

black lung due to carbon/dust

Question 12

Which pigment is responsible for the yellow color of plasma/adipose of ruminants?

Answer 12

B-carotene

Question 13

Tetracyclines and fluoride

Answer 13

• Deposited in MINERALIZING teeth (young animals)
• Stains teeth yellow/brown
• fluorescent
• EXCESS fluoride weakens and darkens enamel

Question 14

Describe two diseases associated with hemoglobin

Answer 14

1) Nitrite poisoning
- Nitrate (fertilizer) -> nitrIte (rumen)
- Nitrite converts hemoglobin to methemoglobin (low O2 affinity)
- Chocolate blood
- Sudden death

2) Intravascular hemolysis
- RBCs lysed in vessels
- Pink plasma/serum and red urine due to released hemoglobin
- hemoglobinuria turns renal parenchyma dark red/gunmetal blue
- i.e. Cu toxicity (sheep), Maple leaf toxicity (horses)

Question 15

Describe 2 causes of hematin (modified hemoglobin) accumulation

Answer 15

1) Parasitic hematin
- parasites consume RBCs, convert heme to hematin, leave black migration tracts behind
- i.e. liver flukes (fasciola/fascioloides) in ruminants, lung mite (pneumonyssus) in monkey lung

2) Formalin Pigment
- postmortem change

Question 16

Hemosiderin

Answer 16

• Intracellular iron storage complex
• Macrophages (esp. spleen)
• Disease of XS = hemochromatosis
• Golden-brown deposits in H and E
• Visualized w/ Prussian blue

Question 17

Describe the “life cycle” of heme

Answer 17

1) Senescent RBCs undergo phagocytosis, releasing heme
2) Phagocytes convert heme -> biliverdin
3) Phagocytes convert biliverdin -> bilirubin
4) Bilirubin-albumin complex travels via blood to liver
5) Liver conjugates bilirubin and releases via bile canaliculus to bile duct

Question 18

Melanin

Answer 18

• 1st step of synthesis (tyrosine -> DOPA) is catalyzed by a copper-dependent enzyme (tyrosinase)
• Found in meninges, lungs (sheep, cattle, pigs), oral cavity (ginger cats)

Question 19

Compare and contrast melanoma and melanocytoma

Answer 19

1) Both are cancer of melanocytes
2) Melanoma = malignant
3) Melanocytoma = benign

Question 20

Lipofuscin

Answer 20

• “Wear and tear” from cell membranes
• Cardiac myocytes, neurons
• Harmless

Question 21

Ceroid

Answer 21

• Resembles lipofuscin
• Oxidative stress
• Storage diseases, vitamin E deficiency, cachexia [wasting]

Question 22

Name 2 examples of intraNUCLEAR viral inclusions

Answer 22

1) Herpes

2) Adenovirus

Question 23

Name 2 examples of intraCYTOPLASMIC viral inclusions

Answer 23

DNA: Poxvirus
RNA: Rabies (negri bodies, purple ovals about the size of a nucleolus)

Question 24

Name 2 examples of viral inclusions that are both cytoplasmic and nuclear

Answer 24

1) Paramyxoviruses [para-MIX-o-virus] (CDV, measles)

2) Papillomaviruses

Question 25

Describe appearance of amyloid

Answer 25

- Eosinophilic w/ H and E - Congo-red - Birefringent: apple-green

Question 26

AL amyloid

Answer 26

- Primary - Immunoglobulin light chains from plasma cells Found: anywhere - Skin = plasmacytoma - Systemic = multiple myeloma - Equine nasal amyloidosis = skin, nasal, and conjunctiva of eyes

Question 27

AA antibody

Answer 27

- SECONDARY - Associated w/ inflammation - Serum amyloid A produced by hepatocytes Found in: - Liver - Kidney - Splenic RED pulp

Question 28

AA familial-primary

Answer 28

- Shar-pei dogs - Abissinian cats - Renal medulla/systemic

Question 29

Islet amyloid peptide

Answer 29

- Secreted by pancreatic B cells - Deposit in pancreatic islets of cats/human beings - May precede diabetes

Question 30

Fibrin/hyaline and 2 associated conditions

Answer 30

- Indicate vascular damage - Lung: ARDS - Kidney: Disseminated intravascular coagulation

Question 31

Gout consists of ____, deposits of which are called _____ and are found in _____ and ______.

Answer 31

Uric acid Tophi Birds and reptiles

Question 32

Cholesterol deposits

Answer 32

Found in: - Necrosis - Hemorrhage - Chronic granulomatous inflammation (they elicit) Examples: - Cholesteatomas: cholesterol granulomas in lateral ventricles of horse brains - Hypothyroidism-induced atherosclerosis in dogs

Question 33

Dystrophic calcification

Answer 33

- Deposition of Ca due to loss of intracellular regulation - Ca levels/metabolism normal - Micro: basophilic stippling (esp. mitochondria) - Macro: fine white granules - i.e. white muscle disease, tuberculoid granuloma, parasitic granuloma, calcinosis cutis (in hyperadrenocorticism - XS corticosteroids)

Question 34

Metastatic calcification

Answer 34

- Deposition of Ca in normal tissues; hypercalcemia 2ndary to metabolic disturbance 4 causes 1) Renal failure - Retention of phosphates 2) PTH 3) Vitamin D toxicosis 4) Neoplastic bone destruction Affects mainly: 1) Gastric mucosa 2) Kidneys 3) Lungs 4) Systemic arteries 5) Pulmonary veins

Question 35

Primary hyperparathyroidism is rare. Name 3 causes of 2ndary hyperparathyroidism

Answer 35

1) Canine lymphoma 2) Anal sac apocrine gland adenocarcinoma (cancer of mucus-secreting cells) 3) Multiple myeloma (plasma cell tumor in bone marrow)

Question 36

Name 2 causes of Vitamin D toxicosis

Answer 36

1) Calcinogenic plants (Cestrum, Solanum) | 2) Cholecalciferol rodenticides

Question 37

Which tissues are targeted by vitamin D toxicosis?

Answer 37

Heart (L ventricle) Vessels Lung Mneumonic: LL -> Left ventricle and Lungs

Question 38

What is heterotopic ossification, what does it look like, where does it occur, and what is its prognosis?

Answer 38

1) Bone formation outside of skeleton 2) Grossly as hard spicules 3) [Benign] Canine mammary tumors and lungs of old dogs 4) Insignificant