Images

Question 1

Pathological process
top vs bottom

Answer 1

top - renal amyloidosis
bottom - renal lipidosis

Question 2

Pathological process

Answer 2

Dilated cardiomyopathy - eccentric hypertrophy

Question 3

Adaptive tissue response

Answer 3

Atrophy

Question 4

Distribution

Answer 4

Focal

Question 5

Distribution

Answer 5

Multifocal

Question 6

Distribution

Answer 6

Diffuse

Question 7

Demarcation

Description

Interpretation

Morph diagnosis

Answer 7

• Well demarcated
• DESCRIPTION: Spleen: There is a focal, well demarcated, raise, approximately 10cm diameter nodule arising from the splenic parenchyma. The nodule has a smooth surface and is mottle pale pink/orange to dark red with some regions of pallor within the mass forming smaller, discrete nodules.
• INTERPRETATION: Spleen: There is a focal, well demarcated, raise, approximately 10cm diameter nodule arising from the splenic parenchyma (nodular hyperplasia v neoplasia v inflammation/abscess/granuloma). The nodule has a smooth surface and is mottle pale pink/orange to dark red with some regions of pallor within the mass forming smaller, discrete nodules.
• MORH DX: Spleen: Mild, focal, chronic nodular hyperplasia.

Question 8

Demarcation

Answer 8

Poorly demarcated

Question 9

• Describe the abnormality
• Interpret

Answer 9

• DESCRIBE: Within the skin is a focal, approximately 1cm diameter, raised, black mass.
• INTERPRET:
  Haired skin: Cutaneous melanoma.
  Haired skin: Focal, mild, subacute to chronic nodular dermatopathy
  Haired skin: Focal, mild, subacute to chronic cutaneous neoplasm

Question 10

• Describe the abnormality
• Interpret

Answer 10

• DESRCIBE: Multifocally, throughout the grey and white matter of cerebral cortex, the brainstem and the hippocampus are approximately 12, irregularly shaped foci of dark red to black discolouration; some of these are slightly raised and some have cavitation or depression within the centre. Some of these are rimmed by bright red discolouration and there are multiple, smaller foci of bright red discolouration also present; some of these are pin point sized.
• INTERPRET:
  Brain: Multifocal, severe, acute to subacute cerebral haemorrhage or haemorrhagic infarction or haemorrhagic necrosis
  Brain: Metastatic melanoma or metastatic neoplasia
  Brain: Multifocal, severe, acute to subacute metastatic neoplasia

Question 11

• Describe the abnormality
• Interpret

Answer 11

• DESCRIBE: Multifocally, throughout the grey and white matter of cerebral cortex, the brainstem and the hippocampus are approximately 12, irregularly shaped foci of dark red to black discolouration; some of these are slightly raised and some have cavitation or depression within the centre. Some of these are rimmed by bright red discolouration and there are multiple, smaller foci of bright red discolouration also present; some of these are pin point sized.
• INTERPRET:
  Oral cavity or mandible: Oral neoplasia
  Mandible: Focally extensive, severe, chronic oral neoplasm
  Mandible: Focally extensive, severe, chronic oral mass with ulceration and haemorrhage

Question 12

Pathological process

Answer 12

Supporative peritonitis

Question 13

Pathological process

Answer 13

Ascites

Question 14

Pathological process

Answer 14

Oedema in the lung

Question 15

Pathological process

Answer 15

Passive hyperemia - enlarged darkened liver due to RHS heart failure

Question 16

Pathological process

Answer 16

Passive hyperemia - twisted intestine

Question 17

Pathological process

Answer 17

Ischemia causing infarction

Left - Acute cortical infarct
Right - Subacute to chronic spinal cord infarct

Question 18

Pathological process

Answer 18

Acute splenic infarct

Question 19

Pathological process

Answer 19

Acute myocardial infarct

Question 20

Pathological process

Answer 20

Left - Acute renal infarct
Right - Chronic renal infarct

Question 21

Hyperemia/haemorrhage - Classification based on size
What size do you call this?

Answer 21

Petechiae

Question 22

Hyperemia/haemorrhage - Classification based on size
What size do you call this?

Answer 22

Purpura

Question 23

Hyperemia/haemorrhage - Classification based on size
What size do you call this?

Answer 23

Ecchymosis

Question 24

Hyperemia/haemorrhage - Classification based on site
What do you call this?

Answer 24

Haematuria

Question 25

Hyperemia/haemorrhage - Classification based on site What do you call this?

Answer 25

Hemopericardium

Question 26

Hyperemia/haemorrhage - Classification based on site What do you call this?

Answer 26

Hyphemia

Question 27

Pathological process

Answer 27

Pleural effusion/Hydrothorax Due to LHS heart failure

Question 28

Pathological process

Answer 28

Ascites/Oedema de to decreased intravascular oncotic or osmotic pressure

Question 29

Pathological process

Answer 29

Oedema due to lymphatic obstruction (Biliary adenocarcinoma with secondary lymphatic obstruction and chyle stasis)

Question 30

Pathological process

Answer 30

Oedema due to toxin eg. enterotoxic strains of Ecoli

Question 31

Pathological process

Answer 31

Brain active hyperemia

Question 32

Pathological process

Answer 32

Splenic engorgement - passive hyperemia

Question 33

Pathological process

Answer 33

Petechial conjunctival haemorrhage

Question 34

Toxic cause? Pathological process

Answer 34

Rodenticide toxicity = severe peritoneal, hepatic and pulmonary haemorrhage

Question 35

Pathological process

Answer 35

Arterial thrombosis

Question 36

Pathological process

Answer 36

Infarct - thrombus in the cranial mesenteric artery

Question 37

Pathological process

Answer 37

Adrenal cortical haemorrhage endotoxic shock

Question 38

Describe the abnormalities. Do you think these lesions are clinically significant? What pathological processes might cause this appearance? How might you test your hypotheses? Construct a morphological diagnosis

Answer 38

- Describe the abnormalities (Unit Guide) Something has been added (swelling)! The subcutaneous tissues ventral to the mandible, neck, and brisket are markedly swollen, each in a focally extensive manner (oedema – although also consider less likely alternatives – see below). The left jugular vein is extremely prominent and bulging within the jugular groove. - Do you think the lesion(s) would have been clinically significant prior to death? Yes, due to our proposed pathogenesis. What other CS might this animal be showing, and what other gross changes might you have seen in other organs at PM? - Try to determine what pathological process is responsible for the changes. Be as specific as possible! Vascular disturbance, specifically oedema (although, at least grossly, we could not be 100% sure that the ventral tissue swelling might not be due to something else being added e.g. haemorrhage, inflammatory cells, neoplastic cells, acellular deposit). In real life you’d be able to demonstrate pitting on palpation consistent with oedema. Jugular distension – obstruction to venous return, pericarditis causing compression of cardiac chambers and impaired cardiac filling - Construct a morphological diagnosis for the 1st image only Ventral subcutis of mandible, neck and brisket: severe, subacute oedema with jugular distension/congestion.

Question 39

Describe the abnormalities. Do you think these lesions are clinically significant? What pathological process do you think is occurring? Construct a morphological diagnosis. What is the most likely pathogenesis?

Answer 39

- For each image, describe the abnormalities Things have been added AND taken away! There is a large amount (likely > 1L) of dark red-purple liquid (unclotted blood) filling the left hemithorax and also present pooling in the left retroperitoneal space. This added fluid has resulted in collapse of the right lung lobes and dorsal displacement of the heart off the sternum. Also, there is generalised pallor of all of the visible organs/tissues (blood loss anaemia/hypovolaemia). - Do you think the lesion(s) would have been clinically significant prior to death in each case? Yes! The sheer volume of blood loss tells us that, plus the fact the organs/tissues are pale. As a rough rule of thumb, you can estimate a dog’s blood volume by using the rough guide of 70-90ml/kg. So, for an estimated 25kg dog, it would have an approx blood volume of 1.75L-2.25L. CS of blood loss manifest as soon as you lose 15% or more of your blood volume, with anything from 20-30% and above being life-threatening (> hypovolaemic shock) – so obviously such a huge volume of blood loss was catastrophic in this patient. - Try to determine what pathological process is responsible for the changes. Be as specific as you can! Vascular disturbance, specifically haemorrhage causing anaemia and hypovolaemic shock. Defect in secondary hemostasis most likely with body cavity haemorrhage. - Construct a morphological diagnosis for each image Dog: severe, acute diffuse haemothorax (with haemabdomen, pulmonary atelectasis, cardiac malpositioning and anaemia/hypovolaemia) - What is the likely pathogenesis of the abnormality (ies)? Clue – this is a fresh PM yet the blood is unclotted! Body cavitary haemorrhage is suggestive of a disorder of secondary haemostasis. Anticoagulant rodenticide ingestion > toxins antagonise vitamin K, which interferes with the normal synthesis of coagulation protein factors in the liver (specifically γ-carboxylation activation of coagulation factors II, VII, IX, and X and proteins C and S); thus, adequate amounts are not available to convert prothrombin into thrombin > following a latent period, dependent on the specific toxin, species, dose, and activity, during which clotting factors already present are used up > platelet plugs formed by primary haemostasis cannot be stabilised > haemorrhage. So, because the vit K-dependent factors are placed in both the intrinsic and extrinsic arms of the CC, both PT and PTT are going to be prolonged… This fact will help you diagnostically.

Question 40

Describe the abnormalities. Do you think these lesions are clinically significant? What pathological process do you think is occurring? Construct a morphological diagnosis. What is the most likely pathogenesis?

Answer 40

- For each image, describe the abnormalities Something has been added! There are multifocal to coalescing flat round well demarcated pinpoint/1mm to 5mm red to purple spots scattered over the skin surface (petechiae and ecchymoses). - Do you think the lesion(s) would have been clinically significant prior to death in each case? Yes – this is suggestive of a defect of primary haemostasis i.e. platelet number and/or function. If there are CS, it means that number and/or function is dangerously low. If an individual cannot form a stable platelet plug, then any otherwise relatively insignificant trauma could be catastrophic. - Try to determine what pathological process is responsible for the changes. Be as specific as you can! Vascular disturbance, specifically petecchial (and ecchymotic) haemorrhage - Construct a morphological diagnosis for each image Dog skin on dorsum: mild, acute, multifocal to coalescing petechiae (note: you know it is acute because there are no colour changes seen that would be attributable to resolution of haemorrhage with haemoglobin recycling – think of the colour progression a bruise goes through as it resolves) - What is the likely pathogenesis of the abnormality (ies)? Petecchiae are suggestive of a defect of primary haemostasis i.e. platelet number and/or function. E.g. Immune-mediated thrombocytopaenia > low platelet count and therefore function > inability to form stable platelet plugs with the microtrauma of everyday life > petechiae

Question 41

Describe the abnormalities. Do you think these lesions are clinically significant? What pathological process do you think is occurring? Construct a morphological diagnosis What is the most likely pathogenesis?

Answer 41

- Identify the organ/ tissue Eye, eyelid, conjunctiva - Describe the abnormalities Diffusely, the conjunctival tissue is swollen, protruding into the ocular orifice and obscuring the cornea. The conjunctival tissue is bright pink to red and small blood vessels are prominent and bright red. The tissue is diffusely shiny. - Do you think the lesion(s) would have been clinically significant? Yes – the conjunctival is swollen and is obscuring vision. The presence of swelling and redness suggest a painful process Try to determine what pathological process is responsible for the changes. Vascular disturbances, specifically active hyperaemia (responsible for the bright pink to red change and prominent blood vessels), oedema (responsible for the wet appearance - Construct a morphological diagnosis Conjunctiva: severe, acute, diffuse hyperaemia and oedema (or conjunctivitis) - What is the likely pathogenesis of the abnormality (ies Feline herpesvirus conjunctivitis is a form of primary conjunctivitis caused by the highly infectious feline herpesvirus (FHV-1). Herpesvirus infection is the most common cause of conjunctivitis in cats. FHV-1 preferentially infects mucoepithelial cells of the tonsils, conjunctiva and nasal mucosa, but there is also significant infection of corneal epithelial cells. The resultant infection is characterised by rapid replication and acute cellular damage leading to cytolysis. Infected cells release pro-inflammatory molecules including prostaglandins, leukotrienes and cytokines including TNF-α, IFN-α, IL-1 and IL-12  vasodilation and inc vascular permeability due to acute inflammatory mediators

Question 42

Describe the abnormalities. Do you think these lesions are clinically significant? What pathological process do you think is occurring? Construct a morphological diagnosis What is the most likely pathogenesis?

Answer 42

- Organ: Aorta and aortic bifurcation with surrounding adipose tissue - Describe the abnormalities The vessel has been opened to show that ~90% of the lumen contains a cylindrical dark red to pale pink to yellow gelatinous object which obstructs the lumen (thrombus). - Do you think the lesion(s) would have been clinically significant prior to death? Yes – this is a major vessel, so luminal obstruction is significant, particularly given this looks like it would have completely occluded laminar flow! - Try to determine what pathological process is responsible for the changes. Be as specific as possible! Thrombosis - Construct a morphological diagnosis Aorta / aortic bifurcation: severe, acute to subacute, focally extensive, aortic thromboembolism - What is the likely pathogenesis of the abnormality (ies)? Thrombosis - Virchow’s triad (hypercoagulable blood, sluggish/ turbulent blood flow, endothelial cell damage) This condition is known as FATE – Feline Aortic thromboembolism. Cats with cardiac disease, often hypertrophic cardiomyopathy, have an enlarged left atrium which causes turbulent blood flow and the formation of micro-thrombi or sometime large intra-atrial thrombi  portions break off (thromboemboli) and travel into the aorta to lodge at the bifurcation and cause occlusion of blood flow to the caudal half of the body.

Question 43

Path process Other organ may it effects?

Answer 43

Passive hyperemia Heart

Question 44

Most likely dx How old is the lesion

Answer 44

Hemorrhagic infarct 1-2days

Question 45

Image: the opened abdomen from a dog which died from rodenticide toxicity. which coag factors most likely deficient in this patient?

Answer 45

II, VII, IX, X

Question 46

Cause

Answer 46

Venous obstruction

Question 47

Pathological term

Answer 47

Haematuria

Question 48

Image: A sagitally sectioned head from a horse that was bleeding from the nose. The horse did not respond to treatment and was euthanased. Describe the abnormalities visible in the image. (5 marks)

Answer 48

There is an aggregate of red-black gelatinous material (1) occupying ~1/2 the ventral aspect of the ethmoid turbinates (1) and extending into and filling the sphenoid sinus (1). Generally the nasal mucosa is a mottled dark red/ black (1) particularly the ventral nasal conchae and to a lesser degree the dorsal nasal conchae (1).

Question 49

Image: Intestines from a pig. The purple circles show where the intestines have been opened so you can see the intestinal contents.The mesenteric lymph nodes have been cut open in the centre. a. Identify and describe any vascular disturbances visible in the image. (9 marks) b. For one of the vascular distrubances described, suggest a possible cause and outline the mechanism. (3 marks)

Answer 49

- A. 1. The mesenteric, intestinal serosa and lymph node vessels are dark red and prominent (1) (hyperaemia(1) mark). 2. There are rare, irregularly flat foci of red discolouration (1) on the intestinal serosal surface (1) and visible on and within the lymph node (1). The cut surface of the lymph node is mottled dark red (1) (haemorrhage(1)) 3. The serosal surfaces are very shiny (1) (oedema(1)) - B. Infectious agent in the intestine causing inflammation (1)  vasodilation occurs to bring more blood containing inflammatory mediators and cells to the site of inflammation (1)  hyperaemia (1) or oedema (1)

Question 50

Pathological term

Answer 50

Epitaxis

Question 51

Pathological term

Answer 51

Hyphemia

Question 52

Hyperemia/haemorrhage - Classification based on size What size do you call this? Common with what kind of disease

Answer 52

Generalized petechia and ecchymoses Immune-mediated thrombocytopenia

Question 52

These symptoms (pale and jaundiced/icteric) are common in what disease?

Answer 52

Immune mediated hemolytic anemia (IMHA)

Question 53

Describe the pathology Morph dx Type of hypersens reaction

Answer 53

- Describe the pathology: Focally extensive, unilateral (left image)/bilaterally symmetrical (right image) swelling on the distal muzzle/maxilla, primarily affecting the haired skin behind the nose - Morph dx: Bilateral asymmetrical subcutaneous mandible/maxilla: severe, acute oedema - Type of hypersens reaction: Type 1 (IgE)

Question 54

Labored breathing , Quiet, tachycardia Describe the pathology Morph dx Type of hypersens reaction

Answer 54

- Describe the pathology: The mucous membranes within the oral cavity are diffusely pale and yellow - Type of hypersens reaction: Type 2 (IgG, IgM)

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