Pathology

Prof. Dr. Osman A. Attallah Visitor Prof.

Prof of Pathology Department of Patahology, Faculty of Veterinary Medicine, Zagazig University

Egypt Email: dr dr_atallah_o_a@hotmail.com atallah o a@hotmail com Mobile: +2 - 0197434781

Systemic Pathology

(1)

B

A

Organ: g Intestine (rabbit) Stain:: H&E. Lesion:

Acute A necrotic enteritis.

Micro.:The

intestinal mucosa suffered coagulative necrosis, particularly the upper layer (A) Hyperemic blood vessels and inflammatory (A). cells (B) are seen in the deep layer of the mucosa.

B B

â—ŒŮ? A

(2)

b

a

Organ : Intestine.

Stain : H & E. L i : Lesion

a

Chronic catarrhal enteritis

b Micro.:Most of the columnar epithelial lining

off the h i intestine i chnged h d to goblet bl cells ll (metaplasia).The nuclei of the goblet cells are on their basement membrane and excessive mucin exists i t in i the th upper portion ti ( ) Th lamina (a).The l i propria and the sbmucosa present congested blood vessels and infiltration with lymphocytes and macrophages (b) The lumen of the intestine contains numerous dequamated epithelium.

a

(3) a

b

Organ: Intestine.

Stain: H&E. Lesion:

Acute catarrhal parasitic enteritis.

b

Micro:

The epithelial covering of the villi is partially desquamated.The mucosa presents numerous hyperemic h i blood bl d vessels, l b id besides rd numerous neutrophils (a).The parasite (3 stage larvae of Strongyloides westeri) (arrow) appear as bluish masses (b) in the intesinal lumen and mucosa.

a

(4)

Organ : :Intestine (Rabbit) Stain : H & E. Lesion :

a

Chronic catarrhal enteritis.

c Micro.

b

d

The epithelial lining of the intestine contains the various developmental p stages g of Eimeria (schizonts, merozoites, trophozoites and oocysts) (a), and numerous goblet cells (b). The lumen of the intestine contains numerous oocysts and necrotic epithelium i h li ( ) The (c).

Th mucosa contains i hyperemic h i blood bl d vessels besides numerous inflammatory cells (d). :

a b

b

(5)

Organ : Intestine O I i (Chicken (Chi k Stain : H & E. Lesion :

a

Acute A t h hemorrhagic h i enteritis (coccidiosis) b

a Micro : Micro.

The epithelial lining of the bottom of the crypts of Lieberkuhn contain the various developmental stages of Eimeria (a).The mucosa contains numerous congested blood blood-vessels, vessels, erythrocytaes and inflammatory cells. Sloughed villi with oocysts (b) are seen in the intestinal lumen.

a

(6)

Organ: Abomasum.

Stain: H&E. Lesion:

c

Chronic ulcerative gastritis

b b

Micro.

: Ulceration (a) of the gastric mucosa, which shows hyperemic and thrombosed blood vessels l (b) besides b id i filt ti with infiltration ith neutrophils, t hil lymphocytes and macrophages (c).

a c b

(7)

a

: Peritoneum (Chick).

St i Stain : H & E. E Lesion :

Organ

b

Chronic C i necrotic i peritonitis.

Micro.:

Focal thickening of the visceral peritone m (covering peritoneum (co ering the intestine) by b fibro s fibrous connective tissue with caseated foci (a) surrounded with macrophages and lymphocytes (b). The fibrous connective tissue shows aggregation of granulocytes

a b

(8)

a

Organ : Liver.

Stain : H & E. Lesion:

a

Acute toxic inflammation i (hepatitis)

a

Micro.

a

Diffuse cenrolobular necrosis infiltrated with eosinophils, and partially replaced with blood (a). Few lymphocytes are seen in the portal tracts :

a

( ) (9)

Organ : Liver.

Stain : H & E Lesion:

b

Micro. : Focal

a

coogulative necrosis (a) of the hepatic p pparenchyma y ((a)) surrounded byy a zone of neutrophils, macrophages and lymphocytes (b). The necrotic areas are infiltrated with macrophages and lymphocytes.

Chronic infectio s ous inflammation (hepatitis) (hepatitis). b

b

a

a b

(10) Organ : Liver (Mouse).

Stain : H & E. Lesion:

c

Chronic Parasitic inflam( p ) mation(hepatitis) a

.

b

Micro. :Schistosome-eggs (a) are

surrounded b eosinophils, by i hil lymphocytes l h andd macrophages h (b) (b).

The hepatic cells reveal some degenerative changes. The hepatic cells, adjacent to the schistosome hi t worm (c), ( ) show h pressure atrophy. t h

a b

c

(11)

a

Organ g : Liver.

Stain : H & E. Lesion :

Migratory tracks of C ti Cysticercus tenuicollis.

Micro. : Focal

replacement of the hepatic parenchyma with migratory tracks (a). (a) The tracks are represented by crescent-ically lamellated fibrinous material, trapp- ing erythrocytes and leukocytes. Macroph Macrophages, lymphocytes, eosinophils and siderocytes are surrounding the tracks and infiltrating the portal tracts. The oncospheres are represented by cavities lined with filamentous cells on an eosinophilic hyalinized layer.

a

(12)

Organ : Liver.

Stain : H & E. E Lesion :

IIndividualized di id li d hepatic cells.

a

Micro.

:Complete dissociation of the hepatic cords to appear as individual hepatic cells with blood among them.

The portal tracts (a) are intact.

a

(13)

b

a

b

Mi Micro.

c

The hepatic parenchyma is extensively replaced by hyperplastic adenomatous bile ducts (a), (a) containing the parasite (b). Such ducts are surrounded with excessive fibrous tissue proliferation infiltrated with macrophages, siderocytes, lymphocytes and eosinophils (c). Thrombosed blood vessel were encounteere

Organ : Liver.

Stain : H & E. Lesion :

Chronic Parasitic inflam inflam., hepatitis, (Distomiasis)

:

c

b

a

A B )

( ) (14) Organ : Liver (Sheep) Stain : H&E

L i : Lesion A

Micro : Extensive

replacement of the hepatic cells with fibrous tissue ((A). ) Lymy phocytes and macrophages are present. The regenerated hepatic cells formed soild nodules without the normal histologic arrangement of the h hepatic i lobules l b l (B).

(B)

Cirrhosis.

A B

((15)) Organ: :Liver.

Stain: H&E.

a

a

Lesion::

a

Mi : Micro: Micro

The portal tracts are infiltrated with numerous eosinophils , besides some lymphocytes and macrophages (a).. (a)

Chronic eosinophilic p . hepatitis

b

a

a

Micro :The wall of the bile bile--duct is thickened by proliferated fibrous tissue infiltrated with l lymphocytes h t andd plasma l cells ll (a). ( ). Extensive (a) E t i desquamation of the epithelial lining of the bile duct (b) (b)..

16 Organ: Liver (bile duct).

Stain: H&E. Lesion:

Chronic catarrhal colangitis.

b a

(17) Organ : Gallbladder Stain:H&E. Lesion :

b a a

a

Micro.:Almost :Almost

complete desquamation desq amation of the epithelial lining with denuded lamina propria (a). The latter is infiltrated with l lymphocytes, h t macrophages, h eosinophils i hil and d neutrophils. Numerous erythrocytes are present (b).

Chronic C i hemorrhagic ulcerative cholecystitis. b

a

(18)

a

Organ : Lung (Rabbit).

St i : H & E. Stain E

Lesion :

a

a

Granulomatous pneumonia ((TB). )

Micro : Tubercle Micro.

nodules (a) are scattered throughout the pulmonary tissue.

Each nodule consists of central aggregation of macrophages or caseated centers surrounsurroun ded with macrophages., lymphocytes and fibrous tissue.

a a

a

(19)

a

b

b b

c

Organ : Lung.

St i Stain : H & E. E Lesion :

Bronchiolectasia.

Micro :The Micro.: Th

bbronchioles hi l are extensively t i l distended with debri and inflammatory cells within their lumina (a). Degeneration and necrosis are seen in i the th walls ll off many bronchioles b hi l together t th with ith leukocytic infiltration (b). The epithelial lining of the affected bronchioles frequently showed sq amo s metaplasia.Collapsed squamous metaplasia Collapsed surrounding s rro nding alveoli al eoli (c).

c c b

(20) C B

A

Micro.:Extensive

replacement of the bronchiolar wall with lymphocytes y p y and macrophages (A).Squamous metaplasia of the epththelial lining of the bronchioles (B) Granulocytes are seen in the lumens of the b bronchioles hi l (C).

(C)

Organ : Lung (Guinea-pig).

Stain : H & E. Lesion:

Chronic C o c Lymphocytic bronchiolitis C

B A

(21)

B

Organ: Lung (sheep).

Stain: H&E. L i Lesion:

A

Parasitic pneumonia (Mullerius capillaries). ill i ) B

Micro.: The

larvae (A) are see in the airvesicles vesicles, surrounded by eosinophilic and lymphocytic infiltration with fibrous tissue proliferation. Chronic focal alveolar emphysema (B) is seen.

B A

(22)

a

Organ : Lung : (Young chicks) Stain : H & E. Lesion :

a a

Micro.: The pulmonary tissue

is extensively t i l replaced l d by b caseated t d nodules d l ( ) (a) surrounded with macrophages and fibrous tissue.

Mycotic pneumonia p

a

a

A )

(23) Organ : Lung ( Adult chickens).

Stain : H & E Lesion :

Aspergillosis.

Micro. :

Focal replacement of the pulmonary l ti tissue with ith caseous necrosis. i Mycelia (A) of the Aspergillus fumigatus are seen.

A

B

((24)) A

C D

Organ g : Lungg ((Camel). ) Stain : H & E. Lesion :

H d tid cyst.

Hydatid t

E B

Micro.:Scolices (A) are

surrounded with b d capsule broad l originating i i ti from f th germ layer the l (B).The germ layer is surrounded with laminated wall (C) without nuclei followed by a thick fibro s connective fibrous connecti e tissue tiss e layer la er (D).The (D) The adjacent alveoli (E) are collapsed

C E

D

A

A

(25)

Orga : Lung (guinea pig). pig) Stain : H & E. Lesion :

Larva migrans.

Micro : Larva Micro.

L (A) off ascaris i is i seen

in the pulmonary tissue with or without inflammation. Focal replace p -ment of the pulmonary tissue with granulomatous nodules. The latter consists of central larva surrounded with eosi- nophilic d b i mixed debris, i d with ith eosinophils i hil and d followed f ll d by a zone of macrophages and giant cells.

A

(26)

Organ : Lung(Dog).

Stain : H & E. E Lesion :

A

Pentastomiasis (Linguatula serrata).

A

Micro.:The

arthropode, with transve- rsely striated cuticle (A), locally destroyed the pulmonary tissue Numerous eosinophils and p g surrounded the arthropop de, filled the macrophages air-sacs and infiltrated the int- eralveolar septa, hyperemia and hemorrh- age are seen.

A

(27)

Organ : Lung.

Stain : H & E. Lesion :

)

Micro.:Almost all the air-vesicles

are filled with ith serofibrinous fib i exudate d t containing t i i numerous neutrophils.Hyperemic pulmonary tissue.

Acute serofibri serofibrinous pneumonia.

C

(28) Organ g :Lung. g Stain :H & E. Lesion :

B

Micro.:

A

Focal replacement of the pulmonary tissue with abscesses ((A)) surrounded with fibrous tissue capsule infiltrated with lympocytes and macrophages (B).

The bronchioles ((C)) are filled with neutrophils, p , and blood vessels are hyperemic.

Chronic suppUrative pneumonia. i C

B

A

(29)

A

Micro :The Micro.: Th interalveolarsepta(A) i t l l t (A) andd pleura l

are thickened with fibrinous exudate, inflitrated with lymphocytes and plasma cells. Various stages of pneumonia i are seen in i the h pulmonl ary lobules. l b l

Organ : Lung.

Stain : H & E. Lesion :

Chronic intersinters titial pneumonia

A

B

B

A

Organ : Lung (Rat). ( ) Stain : H & E. Lesion:

B

B

(30)

Aspirated blood.

B

B

Mi Micro.: The normal constituents of blood

are seen in the bronchioles (A) and air-vesicles (B) (B).

A B B

A

A

(31) Organ : Testis (Buck) Stain : H & E. Lesion :

A

Micro.:

Some semininiferous tubules are overdistended with sperms (A) causing pressure atrophy and necrosis of its epithelium The retained. sperms are frequently necrotic and calcified. Many seminiferous tubules are lined by one or two layers of germ cells (B).

31

Spermatostasis.

A

(32)

Organ : Testis (Dog).

Stain : H & E. Lesion :

Seminoma.

Micro.:Large

polyhedral or round discrete cells with large hyperchromatic nuclei and prominent nucleoli are occluding the lumina of the seminiferous tubules.

(33) Organ : Testis (Buck) Stain : H & E. Lesion:

Arrested spermatogenesis. i

Micro.:The

seminiferous tubules are widelyy separated p byy edema. Theyy are lined with spermatogonia, primary and , secondary spermatocytes besides Sertoli cells.The lumina of some tubules contain desquamated and necrotic germ cells. ll

(34)

Prepuce

„

(

Micro.: Papillary

projections of the mucosa with hyperplastic mucosal lymph follicles. follicles The mucosa is infiltrated with macrophages,plasma cells and lymphocytes.

Organ g : Prepuce p Stain : H & E. Lesion :

Chronic serous posthitis.

A A A

(35)

Organ : Uterus.

Stain : H & E. E Lesion :

Miliary tuberculous endometritis.

Micro.:Numerous

y young g tuberculous nodules(A) are scattered throughout the endometrium.Each tubercle nodule usually consists of central caseation necrosis followed byy macrophages and giant cells of the Langhan's type and finally lymphocytes and fibrous tissue.

A A

(36)

A A

Organ : Uterus (Sheep) Stain : H & E. E Lesion :

Chronic cystic catarrhal endometritis.

Micro. : Numerous cystic uterine

glands (A) are lined li d by b flattened fl tt d epithelium.Excessive ith li E i fibrous tissue proliferation infiltrated with lymphocyte, plasma cells and macrophages among the cystic c stic uterine terine glands. glands

A

A

(37)

A

B

Organ: Uterus (ewe).

S i : H&E. Stain & Lesion:

Chronic Ch i necrotic ti endometritis

Micro.:About

1/3 of the luminal lamina A propria is replaced by b necrotic debris, debris mixed mi ed with macrophages, lymphocytes and plasma cells (A). Some uterine glands are cystic and contain eosinophilic debris (B).

(B) .

B B

(38) A

Organ : Udder (Cattle).

Stain : H & E. L i : Lesion

Chronic diffuse lobular tuberculous mastitis. mastitis

Micro.:Diffuse

infiltration and/or replacement of the affected lobules with macrophages, giant cells of the Langhan's type (A), lymphocytes, plasma cells and fibrous tissue i proliferation lif i without ih i involvement l off the h interlobular septa.

A

AA

B

(39) Organ : Udder (Cattle) Stain : H & E. Lesion :

Chronic serous mastitis.

Micro. : Acini of some lobules are cystic (A)

p Fibrous tissue with flattened epithelium. proliferation, infiltrated with lymphocytes and plasma cells, is seen among the acini. Hyperplastic epithelial p liningg of the lactiferous ducts ((B). )

B

B B

(40)

Organ g : Chorion (Intercotyledonary zone).

Stain : H & E. Lesion:

Adventitial placentation.

Micro.: i Newly

formed placentome-like structure with absence of thrombosis.

(41)

Organ : Kidney (Cattle).

Stain : H & E. Lesion :

Acute suppurative ti Nephritis (embolic nephritis).

Micro. : Focally

scattered infla- mmatory cells, ll mainly i l neutrophils, t hil throughout th h t the th cortex. t Areas of liquefactive and coagulative necroses could be seen.

A

(42)

Organ : Kidney O Kid (C l ) (Cattle).

Stain : H & E. Lesion :

Pyelonephritis.

Micro :Suppuration Micro.: S ti and d sloughing l hi

of the renal papillae. Scattered focal suppurative areas, particularly in the medulla (A).

A

(43)

Organ : Kidney.

Stain : H & E. Lesion:

Chronic nonsuppurative nephritis h iti (lymphocytic nephritis). nephritis)

Micro. : Diffuse

replacement of the renal parenchyma with lymphocytes and plasma cells.

The adjacent renal tubules suffered atrophy with thickened and hyalinized basement membrane.

Di Dissociation i ti off the th renall epithelium, ith li i some in locations, to form syncytium.

(44)

Organ g : Kidneyy (Rabbit).

Stain : H & E. Lesion :

Hydronephrosis.

Micro. : Atrophy Of the renal paren-

chyma with cystic dilatation of the renal tubutubu les and excessive fibrous tissue proliferation.

B B

A

(45)

Organ :Kidney.

Stain :H & E. Lesion:

Ckronic lymph lymphocytic cystic p nephritis

Micro: Diffuse

replacement of the renal parenchyma h with ith fibrous fib ti tissue i filt t d with infiltrated ith lymphocytes and plasma cells (A). Cystic dilatation of the renal tubules (B). .

B B

A

(46)

A B

Organ : Urinary bladder (Sodium chlorde toxicosis) of a puppy.

Stain : H & E. Lesion :

Eosinophilic cystitis.

Micro. : Desquamated epithelium (A) with congestion and hemorrhage (B) in the Mucosa, Mucosa besides eosinophilic infiltration

A

B

A

(47)

B

Organ : Urinary bladder (Sodium chloride toxicosis of sheep).

Stain : H & E. Lesion: i

Desquamation q and hemorrhage.

Micro. : Desquamated epithelium (A) mucosal congestion and hemor- rhage (B).

with

B

A

(48)

A

Organ : Brain (Cow).

S i : H & E. Stain Lesion : A

Mi Micro.: The necrotic nervous tissue is

replaced by cavities (A) surrounded by fibrous astrocytes .

EncephaloE h l malacia.

A A

A

A

(49)

Organ : Brain (Hippocampus of dog). dog) Stain : H & E. Lesion :

Intracytoplasmic y inclusion body (Negri body).

Mi Micro. : Large oval or rounded eosinophilic

intracytoplasmic inclusion bodies (Negri bodies) are seen in the large neurons (A), (A) they are of variable numbers and sizes.

A

A

(50)

Organ : Cerebellum (Cow).

St i Stain : H & E. E Lesion :

IIntracytoplasmic t t l i inclusion body (Negri body). body)

Micro. : Large oval or rounded eosin-

ophilic intracytoplamic inclusion bodies (A) are seen inside the Purkingiecells, they are of variable numbers and sizes.

A

(51) B

A

Micro. : Numerous microglia (A) are seen

around the degenerated neurons (satellitosis).Other neurons are being phagocytized (B) by the microglia (neuropha- gia). gia)

Organ g : Brain (Sheep).

Stain : H & E. Lesion :

Satellitosis and neuronophagia neuronophagia.

â—ŒŮ?

(52)

A

Organ : Brain.

Stain : H & E. E Lesion:

Hemorrhagic meningop encphalitis.

B

Micro.: The

meninges and underlyi- ng brain tissue show hyperemia and leukocytic ti infiltration, i filt ti mixed i d with ith numerous erythrocytes (A). Encephalomalacia is evident (B).

A

B

A „

(53) Organ : Brain (choroid pplexus)) Stain : H & E. Lesion :

Chronic eosinophilic choroiditis.

Micro. : The

choroid plexus is highly infiltrated with neutrophils eosinophils, neutrophils, eosinophils macrophages and lymphocytes (A). Hyperemic capillaries and partial destruction of the choroidal epithelial covering are evident.

A

(54)

Organ: Brain (meninges) Stain : H & E. E Lesion:

A

Chronic eosinophilic g meningitis.

B

Micro. : The

A

meningeal covering of the cerebellum is thickened with macro- p phages, g , lymphocytes, eosinophils and neutrophils, ,besides caseous necrosis (A). Oncospheres of Coenuris cerebralis (B) are surrounded with necrotic i debris. d b i Malacia of the adjacent brain tissue is evident.

B

(55)

A

Organ : Brain (Meninges) Stain : H & E. Lesion :

Osseous metaplasia.

Micro.: c o.:Bone o e sp spicule cu e w with bo bonee marrow ow ((A)) in the meninges.

A

A

(56)

Organ : Sciatic nerve (Chi k ) (Chicken).

Stain : H & E Lesion:

B

Neural leukosis A

B

Micro. : Numerous lymphocytes (A) are

seen among, and replacing the degenerated nerve fibers fib (B).

(B)

A

(57)

Organ g : Heart ((Myocary dium). cow.

Stain : H & E. Lesion :

A B

Sarcocystosis.

Micro.: Sarcocysts,

containing a great number of banana shaped bradyzoites (A), are seen inside the muscle fibers (B) without evidence of inflammation.

A B

(58)

Organ : Heart (Myocardi ) turkey. dium), t k Stain : H & E. Lesion :

Granulomatous y myocarditis (Fowl –typhoid).

Micro.: Focal replacement of the

myocardium y with numerous macrophp ages and small lymphocytes.

(59)

Organ : Heart (Pericardium), cow.

St i Stain : H & E. E Lesion :

A B

Chronic Ch i fibrinous pericarditis C pericarditis.

C

A

Micro. :

Extensive replacement p of the pericardium with fibrinous exudate containing numerous neutrophils and bacterial colonies (A).

Granulation tissue ((B)) is seen extendingg between the exudate and the underlying muscle (C ).

B

A

C B

(60)

Organ : Heart (Myocardium) buffalo. buffalo Stain : H & E. Lesion :

Fistulous tract.

Micro.: The

tract is lined with basoph- ilic bacterial colonies ((A)) lying y g on necrotic muscle fibers (B).Leukocytes are seen among the necrotic muscle fibers, besides hyperemic capillaries. Partial replacement of the adjacent muscle fibers with C fib bl t (C). fibroblasts (C)

B A

(61)

B

A B

Organ : Heart (Myocardium).

St i Stain : H & E. E Lesion :

Chronic Ch i nonsuppurative myocarditis myocarditis. ◌ِ ◌ِ ◌ِ ◌ِ ◌ِ ◌ِ ◌ِ ◌ِ ◌◌◌◌◌◌◌◌

Micro.: Congested myocardium

which is focally replaced by fibrous tissue infiltrated with round cells (A). Coagulative necrosis of the involved muscle fibers (B); but the Purkingie cells were relatively resist resistant. :

B

A

(62)

Organ : Heart (Myocardium of guinea Pig).

Stain : H & E. Lesion : A

Parasitic myocarditis (N (Neoascarisi vitulorum larvae) larvae).

Micro : Focal Micro.

F l

replacement l t off the th cardiac di muscle fibers with parasitic larvae (A) surrounded with eosinophils besides round andd ovall vesicular i l nuclei(perhaps l i( h sarcolemmal l l nuclei) together with Anitschkow myocytes (mostly derived from the smooth muscle of the media of th small the ll arterioles). t i l ) The Th nuclei l i off the th cardiac di muscle fibers are moderately hypertrophic and vesicular.

A

(63)

A B

Organ : Heart (Myocardium) Stain : H & E. E Lesion :

Myocardial edema and y hyaline degeneration.

Micro. : Widely

searated muscle fibers with clear spaces (A).Some (A) Some muscle fibers are more eosinophilic with darklystained nuclei, and hyperchromatic interstitial nuclei (B).

A B

A B

(64)

Organ : Heart (Myocardium). ) Stain : H & E. Lesion :

Hyperemia and hemorrhage (klebsiella). (klebsiella)

Micro.

: Hyperemic blood vessels (A) and AA

extravasated blood (B) among the muscle fibers.

Large vesicular nuclei of the muscle fibers which are widelyy separated p from each other.

B

(65)

B

A

Organ : Heart (squab) (squab).

Stain : H&E. Lesion :

Cardiac myomalacia.

Micro.: Focal

disappearance of the muscle fibers ((A)) which were p partially y replp aced byy round cells, particularly macrophages. Collapsed saecolemmal sheathes are evident ((B). )

B

A

(66)

Organ : Artery.

Stain : H & E. Lesion :

A B A

Micro. : Adventitia is highly infiltra-

ted with eosinophils eosinophils,macrophages, macrophages plasma cells and lymphocytes (A). Focal replace- ment of the media with aggregations of eosinophils, surrounding foreign remnants (B).

(B)

Chronic eosinophilic i hili arteritis .

A B

(67)

Organ : Artery (Tail of buffalo) Stain : H & E. Lesion :

A

Chronic y p y lymphocytic endarteritis.

B

Mi Micro. : Intema is Highly infiltrated with

lymphocytes (A).Tunica media shows numerous capillaries (B).

A

B

(68)

A

Organ : Artery (Tail of buffalo) Stain : H & E. Lesion :

Thrombosis

Micro. : Recent thrombus (A) is seen.

Mi Dry gangrene is evident.

A

((69))

A

Organ : Lung (Muscular arterioles). Guinea pig.

Stain : H & E. Lesion :

Medial hypertro hypertrophy (and hyperplasia).

A

Micro. : Luminal narrowng or obst- ruction.

Marked thickening of the media by enlarged and proliferated smooth muscle cells (A).

(70)

Organ : Lung (Arterioles).

(Arterioles) Guinea pig.

Stain : H & E. Lesion :

Periarteritis.

Micro. : Perivascular aggregation of

leukocytes with infiltration of the vascular wall. wall

(71)

Organ : Aorta (Cattle).

Stain : H & E. E Lesion :

Caseation and calcification.

Micro.:

Irregular eosinophilic (caseation) and basophilic p ((calcification)) masses of variable sizes are seen in the intema and media.

(72)

Organ : Aorta (Cattle).

Stain :von kossa Lesion:

Caseation and calcification.

Nicro: The calcified areas are stained black .

A

(73)

B

Organ g : Lymph y p node.

Stain : H & E. Lesion :

B

Chronic Ch i serous lymphadenitis.

B A

Micro.. : The capsule Micro p is edematous and infiltrated

with lymphocyts (A).

(A). Depleted lymph follicles of lymphocytes (B) in the presence of hyperplastic histiocytes, particularly in the medulla with h hyperemia, i h hemorrhage, h edema d andd neutrophilic hili infiltration.. infiltration

B

B

٧٤

(74)

Organ :Lymph node.

Stain : H & E..

S Lesion :

Chronic eosin eosinophilic lymphadenitis.

Micro.: Focal

replacement of the lymphoid tissue with eosinophils mixed with neutrophils and macrophages, particularly in medulla.

Hyperemic blood-vessels are seen.

(75)

Organ : Lymph node ( (Cattle). ) Stain : H & E. Lesion :

A

Granulomatous lymphadenitis.

B

Micro.: Focal

replacement of the lymphoid tissue with caseous necrosis (A) surrounded with palisading macrophages (B) and giant cells (Langhans‘type).

A

A B

(76)

Organ : Lymph node (Cattle) (Cattle).

Stain : H & E. Lesion :

A

A

Chronic suppu− rative lymphadenitis.

Micro.: Focal replacement of the lymphoid tissue by neutrophils (A) surrounded with macrophages giant cells and extensive fibrous tiss e proliferation tissue A

(77)

A B

B

Micro.:Extensive replacement of the lymphoid tissue with hemolyzed blood (A),and areas of caseous and fibrinoid necrosis (B) surrounded with neutrophils, eosinophils and macrophages. Periarteritis, hyalinized arterial walls and thrombosis are encountered.

Organ g : Lymph y p node (Baffalo).

Stain : H & E. Lesion :

Chronic hemorrhagic lymphadenitis.

A

B

B

(78)

A

Organ : Lymph node (Baffalo).

(Baffalo) St ain : H & E. Lesion :

Chronic necrotic lymphadenitis.

Micro. : Focal

replacement of the lymph node d with ith caseated t d material t i l (A) surrounded d d with ith fibrous tissue infiltrated with macrophages and lymphocytes (B).

A

B

A

A

(79)

Organ g : Lymph y p node (Guinea pig).

Stain : H & E. Lesion :

Parasitic nodule.

Micro. : Larva of Neoascaris vitulorum (A) iis surrounded d d b by a thi thick k fib fibrous ti tissue capsule infiltrated with few eosinophils. It partially replaced the lymphoid tissue.

A

(80)

Organ : Lymph node.

Stain : H & E. E Lesion :

Diffuse caseation necrosis.

Micro.

: Diffuse replacement of the lymph

node with granular eosinophilic and basophilic debris.

(81)

Organ : Lymph node. node Stain : H & E. Lesion :

Lipidosis.

Micro.

:

Focal replacement of the l lymphoid h id tissue ti with ith irregularly i l l rounded d d clear l vcuoles. Fat necrosis is seen in some vacuoles.

A

(82) Organ : Bursa of Fabricius.

Stain : H & E. Lesion :

Chronic catarrhal bursitis .

Micro : Extensive destruction of the BMicro.:

lymphocytes (A), partcularly at the center of the lymph follicles which frequently extended to involve the whole follicle to be replaced by histiocytes Desquamation of the epithelial lining histiocytes.

(B) is evident. The stroma is hyperemic hemorrhagic and shows histiocytic proliferation

A

(83)

Organ g : Spleen-Dog. p g Stain : H & E. Lesion :

Canine nodular hyperplasia (splenoma). (splenoma)

Micro. : Increased number of

lymphocyt which tes hi h fformed d llarge masses without ith t di distinct ti t central arteries (A). Such lymphoid masses partA ially replaced the adjacent red pulp.

(84)

Organ : Spleen-Dog. Spleen Dog Stain : H & E. Lesion :

A

Hematoma.

Micro.: Subcapsular hemorrhage

(A) which hi h appears h hemolyzed l d and d pressing i on the surrounding tissue.

A

(85)

A

Organ: Liver (Guinea pig) S i Stain : H & E. E Lesion :

Extramedullary E t d ll hemopoiesis .

Micro. : Aggregations of dark basophilic nuclei,of variable sizes,in the hepatic sinusoids (A). Megakaryocytes are seen.

A

( 8 5 ) O r g a n

( 6) (86)

Orga : Chin of a horse Stain : H & E Lesion:

Chronic Eosinophilic y myositis.

Micro. :

Numerous eosinophils with some neutrophils and fibrous tissue focally replaced the chin muscles.The muscles The affected muscles suffered coagulative and caseous necrosis.

(87)

Organ : Skeletal muscle (Rat) muscle.

Stain : H & E. Lesion :

Chronic y fibrinous myositis (klebsiella).

Micro. : Extensive replacementof

the muscle fibers with macrophages, lymphocytes and some neutrophils,together with fibrin network Thrombosed blood vessels.are seen. Fragmentation, of the remainingg muscle fibers,, is found.

(88) Organ : Skeletal muscle ((Duck)) Stain : H & E. Lesion :

B

A

Chronic necrotic myositis (Vit. E. deficiency) deficiency).

Micro. : Extensive

replacement of the skeletal muscles with fibrous connective tissue infiltrated with heterophils and macrophages (A). Hyaline degeneration (B) and Zenker’s necrosis of some muscle fibers are evident.

B

A

A

(89) Organ : Skeletal muscle (Chicken).

Stain : H & E. Lesion :

Hemorrhage (Newcastle disease) disease).

Micro. : Extravasated blood (A) among the

muscle fibers . Notice the avian nucleated erythrocytes.

A

(90)

Organ : Skeletal muscle.

Stain : H & E. E Lesion :

Chronic Suppurative y myositis.

Micro. : Numerous neutrophils are surrounding and invading the skeletal muscles.

The involved muscles lost their nuclei and became more eosinophilic and fragmented. fragmented Interstitial-cells seem to proliferate together with macrophages.