Histopathology colloqium

Icterus retention hepatis canis

• Distended bile duct

• Bile plug

• Kupffer cells hyperplasia

• Distended sinusoids

Thrombis of pulmonary artery branch

• 1- Fresh (Acute)Thrombus: fibrin mesh with embedded erythrocytes and leukocytes

• 2- old (chronic) Thrombus: Hyalinisation of the Thrombus + organization (fibrin)

liver lipidosis

• - peripherally displaced nuclei

• - lipid droplets dissolved in ethanol in vacuoles

• - hardly visible hepatocytes

Myofirbril degeneration of skeletal muscle

• - deep red color

• - desintegrated myofibril surrounded by nuclei

• -some myofibrils are still continuous

1,2,3= more and more zoomed in

Hemorraghic infarction of the spleen

• - sharp transition between necrotic and normal area

- Necrotic area:

1- Haemmorraghe

2- Thrombosis of small vessels

3- hemosiderin pigments + calcium deposit

Liver hepatitis suppurative and necrotizing, multifocal, chinchilla

• -disseminated small necrotic foci and bacterial colonies

• -necrotic foci

• - inflammatory cells within the foci

• - hypereosinophilic remains of hepatocytes

• -congestion of blookd vessels

• -vacuolization of liver parenchyma

• -

Liver hepatitis fibrous, intersitial, chronic and eosinophilic

-pronounced lobular pattern

-interlobar septa thickened, distended and filled with thick fibrous tissue

-infiltration of eosinophil into the fibrous stroma

! difference with cirrhosis= decreased lobules due to pressure of fibrous tissue that doesnt enter the lobule !

Skin actinomycosis, swine

-multifocal to coalescing pyogranulomas — composed of degenerate neutrophils surrounded by macrophages

• - with basophilic filamentous bacterial colonies in the center with eosiniphilic radiating material

-layers of dense connective tissue- fibrosis

-superficial epidermis is necrotic

Stomach ulcer, dog

• -necrotic mass in the lumen (not on this exemple slide)

• - Thrombi within submucosal blood vessels

• - Proliferation of fibrous connective tissue and inflammatory cells infiltration

• - in ulcerative mucosa: loss of mucosal structure, disrupted normal architecture

Small intestine : Necrohemorrhagic enteritis - parvovirosis

-Blunting and fusion of villi

• -loss of apical enterocytes

-bacterial colonies in lumen

-crypts necrosis and regeneration

Pyogranulomatous interstitial nephritis plus phlebitis multifocal, severe, and thrombosis - FIP

-Pyogranuloma

-activated fibroblast

• -thrombosis

• - activation and necrosis of endothelial cells

Lung : Multifocal, necrotic, partly purulent bronchointerstitial pneumonia, subacute

-supposed to have inflammatory foci but not visible on the picture

• -purulent- necrotic bronchitis and bronchiolitis plus neutrophils and macrophages

• - necrosis and exfoliation of pneumocytes

• -eosinophilic inclusions ( not visible on picture)

• -alveolar edema

Brain : Multifocal, perivascular, nonsuppurative meningoencephalitis - rabies

• -blood vessels surrounded by lymphocytes

• -negri bodies

• - degenerated neurons

• -perivascular gliosis

Fibrinous and necrotizing pneumonia

-Disrupted architecture

-Pleura : amorphous eosinophilic mass thickened by fluid (edema) and fibrin

-Bronchial walls are necrotic ( not on the picture)

-multifocal bacterial colonies

-Hemorrhages

Bonchopneumonia , suppurative and embolic

-preserved architecture

-Thrombosis of blood vessel : 1-Fibrin + cell debris+ erythrocytes = fibrinous thrombus

2- Fibrin+ bacteria = spectic thrombus

-Multifocal area of neutrophils, residues of necrotic alveolar septa, bacterial colonies

-parenchymal, interstitial and subpleural edema

Bronchointerstitial pneumonia, lymphohistiocytic, lymphoid hyperplasia

-Lamina propria of bronchi and bronchioli are infiltrated by lymphocytes, plasma cells and macrophages

-hyperplasia of BALT

-in lumen of bronchi, extensive infiltration of neutrophils, macrophages and lymphocytes

-Focal emphysema

-Alveoli are filled with macrophages, lymphocytes, plasma cells and neutrophils

Lymphoma dog

-Disrupted architecture - difuse infiltration of dense round uniform neoplastic cells

• -Tumor extends through capsule into perinodal tissue

• -cytoplasm is eosinophilic

• - tumor necrosis and hemorrhage

Mammary gland: Benign mixed mammary tumor, dog

• -subcutis well demaracated, encapsulated neoplasm

• -2 cell types : luminal epithelial ( form tubules, round nuclei with 1 nucleolus) and myoepithelial (spindle to stellate cells with oval nuclei)+ cartilage (hondrocytes in lacunae)

• -moderate amount of fibrous stroma

Mammary gld adenocarcinoma ( tubulopapillar), dog

-Poorly demarcated, partly encapsulated, partly infiltrative

-tumor cells- tubule and papillary proliferations are less pronounced

• - scant to moderate fibrous stroma

-multifocal area of necrosis

Papilloma- dog

• - exophytic neoplasm from epidermis, form some papillary projections, supported by stroma

• -neoplastic cells progress from a hypertrophied stratum basale to a thickened stratum spinosum

Squamous cell carcninoma

-poorly circumscribed unencapsulated, infiltrative neoplasm composed of polygonal cells, supported by stroma. Nuclei are irregularly round

-cord and island often contains compact eosinophilic lamellation of keratin ( keratin pearls)

-Multifocally stroma is infiltrated with abundant mixed inflammatory infiltrate

Nodular hyperplasia of sebaceous gland, dog

-unencaspulated, well circumscribed mass of multiple lobules which surround ectatic ducts, lined by keratinized stratified squamous ep. filled with keratin

-Lobules are divided into adenomeres

Testicular seminoma

-Multinodular neoplasm composed of round cells, large round, vesicular nuclei.

• -moderate anisocytosis and anisokaryosis

-lymphocytic intratumoral infiltrates

Embolic Myocarditis

-Multifocally, randomly distributed bacterial colonies within small blood vessels and myocytes

-Around bacterial colonies myocytes are swollen with hypereosinophilic sarcoplasm, loss of cross striation and pyknosis

Lymphocytic myocarditis

-Multifocally disrupting the myocardium and endocardium, are lymphocytes, plasma cells and macrophages with some edema

-Cardiac myocytes are swollen with vacuolated or hypereosinophilic sarcoplasm, loss of cross striation and pyknosis

• - Myocytes can be replaced by activated fibroblast that form fibrous tissue

Milliary hepatic tuberculosis

-Multifocally, randomly distributed coalescing granulomas

-smaller granulomas : macrophages and epitheloid cells

-Larger granulomas : necrotic central core ( caseous necrosis) surrounding it are macrophages, lymphocytes, plasma cells and reactive fibroblast and concentric connective tissue

Valvular Endocarditis

-Accumulated layers of irregular deposit on the endothelium valves

• Surface layer : fibrinous, homogenous, pink mass containing bacterial colonies and hemosiderin pigments

• -middle layer : deposit of fibroblast, fibrocytes, collagenous fiber and mononuclear infl. cell

• -last layer: reminder of mitral valves, fragments of undamaged endothelium, collagen and myocytes.

Endocarditis, thrombotic, septic, dog

-Acute : hemorrhage, fibrinous mesh, active fibroblast, neutrophils, macrophages and bacterial colonies

-Chronic : Hemosiderin, intracellular and extracellular accumulation of calcium, thick collagenous fibers, fibrocytes, macrophages, plasma cells

Post necrotic liver fibrosis with nodular regeneration - cirrhosis

-Parenchyma : hepatocytes islet which are various in size and shape - disrupted architecture

-irregular trabecular structures of lobules

• -aggregation of necrotic cell+ rbc+ infl. cells

-Bile stasis

-hemosiderin- central area and within the fibrous tissues

Liver : Centrilobullar necroses, multifocal to coalescing

-architectures of lobules are disrupted

• - hepatocytes are swollen,, hypereosinophilic, with distinct cell border and pyknotic nuclei- necrosis

• -surrounding of collapsed hepatocytes are individuals infl. cells - neutrophils and few macrophages + numerous rbc - hemorrhage

Mastitis : necrosuppurative , bovine

• - Multifocal to coalescing foci

• -Alveoli contains degenerated neutrophils and exfoliatred ep. cells

• -Edema in alveoli and interstitium

• -Tissue necrosis, melting of alveoli filled with pus = abceses

• -Thrombosis of blood vessel, hemorrhage

• -corpora amylacea

Endometritis, suppurative, cytsic, chronic -pyometra

• -Mucosal epithelium : columnar epithelium, hyperplastic, partly exfiolated in the lumen with some suppurative exudate

-Lamina propria : dense infl. cell infiltrate, endometrial glands are ectatic, lined by flattened epithelium and filled with degenerated neutrophils (pus)

-Myometrium: contains perivascular predominantly plasmacytic infiltrate

Nephritis: glomerular, interstitial, chronic

-Glomeruli : fibrin exudate in Bowman’s space, occasionally thickening of Bowman’s capsule, terminal phase= proliferation of fibrous connective tissue ( hyaline appearance)

-Tubules : Degeneration and necroses of tubular epithelial cells, occasionally flattened or ectatic with hyaline cylindres

-Interstitium : Multifocal neutrophils and fibrous tissues

• Bacterial colonies

Hepatitis : necrotizing, acute, multifocal, with basophilic intranuclear viral inclusion bodies

• -Hepatocytes are swollen

• - Subscapular hemorrhage

• -sinusoid dilated with exudate, rbc and mononuclear

• - Interstitium contain occasionally mononuclear infiltrate

• -Intranuclear basophilic inclusion bodies fill almost whole nucleus

Lymphadenitis : Hemorrhagic, acute, pig

-Parenchyma : edematous, severe congestion and hemorrhage

-Peritrabecular sinuses and central area of lymph node without hemorrhages

-thrombosis of capillaries with around it most intense hemorrhages