Cardiovascular gross and histopathic lesions

Pig with history of pyrexia and signs of generalised heart failure. Describe the gross lesion?

• organ = heart

• location = mural endocardium and valvular endocardium

• distribution = multifocal to coalescing

• size = 5mm to 1cm diameter

• shape = circular nodule on mural endocardium, coalescing nodules on valve cusps

• colour = nodules pale yellow / brown with some red mottled discolouration

• consistency = soft-firm intermediate texture

what is the morphological diagnosis for this pig and what is the possible aetiology?

• history - history of pyrexia and signs of heart failure

• gross lesion - multifocal to coalescing pale yellow and red mottled nodules on mural and valvular endocardium, 0.5-1cm diameter, round shape and intermediate texture

• morphological diagnosis = heart, moderate, acute to subacute, valvular and mural, suppurative and thrombotic vegetative endocarditis

• aetiology = E. coli, Streptococcus spp.

Boxer dog died after acute deterioration following chronic congestive heart failure. Describe the gross lesion

• organ = heart

• location = heart base

• distribution = single focal lesion

• size = 15 × 10 cm

• shape = oval and well demarcated

• colour = pale yellow/tan and black mottling

• consistency = firm

• also squashing of vessels due to tumour

what is the morphological diagnosis and origin of lesion?

• history - acute deterioration following chronic congestive heart failure

• gross lesion - 15×10cm oval and well demarcated, pale tan and black mottled, firm tumour at base of heart

• morphological diagnosis = heart, chemodectoma

• origin of lesion = chemoreceptors of the aortic / carotid bodies

Foal died following signs of encephalopathy. Describe the gross lesion

• organ = heart

• location = interatrial septum

• distribution = single focal lesion

• size = 1-2cm diameter

• shape = narrow band of tenuous membrane with feathered edge around periphery

• —> patent foramen ovale

what is the morphological diagnosis?

• history - few days old foal died following signs of encephalopathy

• gross lesion - single focal lesion in interatrial septum, patent foramen ovale

morphological diagnosis - persistent foramen ovale

• mixing of deoxygenated and oxygenated blood —> hypoxia —> ischaemic encephalopathy

Horse in poor body condition, heavy worm burden throughout the GI tract. Describe the gross lesion

• organ = mesenteric artery

• location = arterial lumen

• distribution = focal lesion (within the lesion there are multifocal larvae with few mm length)

• shape = circular lesion filling lumen

• colour = mottled white and red/pink with layering (likely thrombus) within the lumen, vessel wall has pale pink / white discolouration

• consistency = firm

what is the morphological diagnosis and aetiology?

• history - poor body condition horse, heavy worm burden in GI tract

• gross lesion - white and red mottled thrombus occluding arterial lumen, within lumen there are multifocal larvae)

• morphological diagnosis - mesenteric artery, chronic, severe, thrombosing and fibrosing, arteritis with intralesional nematode larvae

• aetiology - Strongylus vulgaris larvae

Cow exhibiting arched back, anxious expression, reluctance to move, groaning when forced sudden movements. Signs decreased in severity, but ongoing reduction in milk yield, food intake and faecal output. Muffled heart sounds and jugular pulses, brisket oedema developed. Describe this gross lesion

• organ = heart (cross section)

• location = epicardial surface

• distribution = diffuse band of fibrous tissue enveloping epicardial surface, with focally extensive lesion at the top right

• colour = band of fibrous tissue is white, focally extensive lesion is yellow and red mottled

• shape = lesion at top right has small projections = fibrin

• consistency = fibrous tissue is firm, while top right lesion is less firm and likely stringy and friable

what is shown in this histology?

Sarcosystis (protozoa parasite) in myocardium - encyst themselves to protect themselves from immune system

what can we see in this high power histology of epicardium?

• fibroblasts = pink stand like cells

• collagen = lots of pink dense material, lack of cells

—> fibrous tissue

what can we see in this medium power histology?

• pink, stringy / mesh-like material = fibrin

what inflammatory cells are these most likely to be within the fibrin?

degenerate neutrophils - can lose the segmentation of nucleus when involved in purulent inflammation

What is the morphological diagnosis and aetiology?

• history - cow displaying signs such as arched back, reluctant to move, groaning with sudden movements. Severity of signs decreased but still reduction in milk yield, food intake and faecal output. Muffled heart sounds and jugular pulses, brisket oedema developed.

• gross lesion - fibrous tissue enveloping epicardial surface, with mottled yellow and red lesion with fibrin

• histology - fibroblasts and collagen in epicardium, protozoa cysts in myocardium, fibrinous tissue with degenerate neutrophils

• morphological diagnosis - epicarditis, severe, chronic, fibrosing, with superficial fibrinous inflammation

• aetiology - coccoid bacteria

3 week old piglet with sudden death after a period of exercise. Describe the gross lesion

• organ = heart

• location = epicardial surface

• distribution = multifocal to coalescing

• size = 80% of epicardial surface affected

• shape = irregular and poorly demarcated

• colour = deep red discolouration —> haemorrhage

what can we see in this histology of myocardium?

• vessels are congested

• erythrocytes outside the vessels = extravascular —> haemorrhage

what can we see in this histology of heart?

• green - degenerate cardiac myofibres (vacuolation of cytoplasm)

• blue - inflammatory cells

—> necrosis

what is shown in this heart histology?

• fibrinoid necrosis - vessel wall replaced with amorphous band of eosinophilic material

—> mulberry heart disease

what is the morphological diagnosis and aetiology?

• history - piglet sudden death after exercise

• gross lesion - multifocal to coalescing, poorly demarcated haemorrhage on 80% of epicardial surface

• histology - multifocal necrotic myocytes, extravascular haemorrhage, multifocal fibrinoid necrosis of arteriolar wall

• morphological diagnosis - necrotising myocarditis, acute, severe, diffuse, with multifocal acute haemorrhages, fibrinoid arterial necrosis and thrombosis

• aetiology - mulberry heart disease due to vitamin E deficiency

Dog showing neurological signs (seizures, depression) and lethargy with muscle weakness. Signs of bilateral heart failure (unproductive cough, exercise intolerance, mild ascites). Describe the gross lesion

• organ = heart

• location = epicardial surface

• distribution = multifocal to coalescing

• size = 80% of epicardial surface

• shape = streaks, poorly demarcated

• colour = pale grey discolouration (pallor)

what can we see in this low power histology of the heart?

multifocal lesions - mainly in myocardium

what can we see in this histology within the lesion?

• green - a few degenerate cardiac myocytes - some vacuolation

• most normal myocardium architecture is gone

• blue - replacement with necrotic material

what does this histology of heart show?

mineralisation —> likely dystrophic calcification due to necrosis

what can we see in this histology at the border between the normal myocardium and the lesion?

presence of inflammatory cells - mostly lymphocytes, plasma cells, and some neutrophils

what does this histology show?

toxoplasma cyst - move through the myocardium, causing the multifocal lesions

what is the morphological diagnosis and aetiology?

• history - dog with seizures, lethargy and muscle weakness. Also showing signs of heart failure (unproductive cough, mild ascites, exercise intolerance)

• gross lesion - poorly demarcated, multifocal to coalescing, pale grey pallor affecting 80% of epicardial surface

• histology - multifocal lesions, necrosis and inflammation, toxoplasma cysts

• morphological diagnosis - multifocal acute to subacute, necrotising, myocarditis with mild to moderate mixed cellular infiltration, and parasite cysts

• aetiology - toxoplasma gondii

10 week old pig with signs of shallow respiration and unwillingness to move, discovered dead the next morning. Describe the gross lesion.

• organ = heart

• location = epicardium

• distribution = diffuse

• size = thin layer covering 100% of epicardium

• colour = pale yellow with areas of reddening (haemorrhage)

• consistency = sticky, with purulent exudate

what is the morphological diagnosis and aetiology?

• history - pig with shallow breathing, unwillingness to move

• gross lesion - thin layer of fibrin, pale yellow with areas of haemorrhage, diffusely covering epicardium, sticky consistency with purulent exudate

• histology - band of fibrillary amorphous eosinophilic material, some fibroblasts, degenerate neutrophils, lymphocytes and plasma cells

• morphological diagnosis - heart, fibrino-purulent epicarditis, moderate, subacute

• possible aetiology - Haemophilus parasuis, streptococcus suis

Pig with signs of dyspnoea and pyrexia, with lameness and neck pain. Describe the gross lesion.

• organ = heart

• location = aortic valve

• distribution = multifocal to coalescing / focally aggregated

• size = 3-5cm

• shape = irregular, nodular and clusters

• colour = dark red

• consistency = firm to friable

what is the aetiology and morphological diagnosis?

• history - pig with dyspnoea and pyrexia, lameness and neck pain

• gross lesion - multifocal to coalescing, dark red, irregular and nodular lesion in the aortic valve, 3-5cm with a firm and friable consistency

• histology - inflammatory cells (neutrophils, lymphocytes, plasma cells) in the valve, thrombus, bacterial colonies

• morphological diagnosis - endocarditis, valvular, subacute , severe, with bacteria

• possible aetiologies - E. coli