Inflammation Laboratory 3 Emphasis: Chronic inflammation and healing. Shannon Martinson: VPM 152: April 2013

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1 Inflammation Laboratory 3 Emphasis: Chronic inflammation and healing Shannon Martinson: VPM 152: April 2013

2 Example A Reproductive tract and colon/rectum from a sheep Previous vaginal prolapse and then prolapsed the rectum

3 Example A Morphologic Diagnosis? Description? Within the vagina and cervical mucosa, there are multifocal to coalescing irregular regions of necrosis with adherent friable tan-yellow material covering the surface. Fibrinonecrotizing vaginitis and cervicitis, multifocal to coalescing, acute (or subacute), severe

4 Example B Calf with a history of a head tilt

5 Example B Description? Pockets of viscous yellow-tan material expand and replace the tympanic bulla and the petrous temporal bone bilaterally

6 Example B Morphologic Diagnosis? Suppurative otitis media and interna (osteomyelitis is also correct), bilaterally extensive, acute (or subacute), severe

7 Inflammation Case 1 Kidney from a sheep with a history of old shearing wounds and subcutaneous abscesses

8 Inflammation Case 1 Description? Within the kidney, there are multifocal-coalescing white to tan nodules present on the capsular surface. These extend into the parenchyma forming irregular to round foci filled with dry, occasionally concentrically laminated, brown-tan material with rare, white, gritty foci. Lesions are surrounded by a fibrous connective tissue capsule.

9 Inflammation Case 1 Description? Also in the adjacent lymph node Within the kidney, there are multifocal-coalescing white to tan nodules present on the capsular surface. These extend into the parenchyma forming irregular to round foci filled with dry, occasionally concentrically laminated, brown-tan material with rare, white, gritty foci. Lesions are surrounded by a fibrous connective tissue capsule.

10 Inflammation Case 1 Disease name: Caseous Lymphadenitis Morphologic Etiology: Corynebacterium pseudotuberculosis Diagnosis? Nephritis and lymphadenitis, granulomatous (I would also accept suppurative), multifocal to coalescing, chronic, severe

11 Inflammation Case 2 Jaw from a cow History of swollen jaw and difficulty eating

12 Inflammation Case 2 Description? The right jaw is markedly swollen and misshapen with raised ulcerative nodular lesions protruding from the gingiva.

13 Inflammation Case 2 Description? On section, the right mandible is distorted and effaced by dense fibrous connective tissue with numerous variably sized pockets of dry tan-yellow exudate

14 Inflammation Case 2 Morphologic Diagnosis? Disease name: Lumpy Jaw Etiology: Actinomyces bovis Osteomyelitis (right mandible), granulomatous, locally extensive, chronic, severe

15 Inflammation Case 3 Tongue from a cow History of protrusion of the tongue, anorexia, and drooling

16 Inflammation Case 3 Description? There is generalized enlargement of the tongue with numerous small (4 10 mm) slightly raised, tan, round to irregular, ulcerated foci on the lateral and dorsal surfaces. On section these round foci extend deep into the muscle forming coalescing nodules surrounded by fibrous connective tissue.

17 Inflammation Case 3 Morphologic Diagnosis? Glossitis, granulomatous, multifocal to coalescing, chronic, severe Disease name: Wooden Tongue Etiology: Actinobacillus lignieresii

18 Ileum from a cow History of pipestream diarrhea Inflammation Case 4

19 Inflammation Case 4 Description? There is diffuse thickening of the wall of the ileum with pronounced folding of the mucosa imparting a corrugated or cerebriform appearance.

20 Inflammation Case 4 Disease name: Johne s Disease Etiology: Mycobacterium avium subsp. paratuberculosis Morphologic Diagnosis? Enteritis, granulomatous, segmental (diffuse), chronic, severe

21 Healing Case 5 Left hind limb from a lamb (unsectioned and sectioned) Lamb was found dead for unrelated reasons

22 Healing Case 5 Medial view (unsectioned) Saggittal section Description? There is a non-union fracture in the distal physis of the left femur with dorsal displacement of the proximal fracture end. Spanning the fractured ends and stabilizing the region, there is nodular to irregular mass of dense firm (fibrous connective tissue) to hard (bone) tissue.

23 Healing Case 5 Medial view (unsectioned) Saggittal section Description? Fracture ends There is a non-union fracture in the distal physis of the left femur with dorsal (anterior) displacement of the proximal fracture end. Spanning the fractured ends and stabilizing the region, there is nodular to irregular mass of dense firm (fibrous connective tissue) to hard (bone) tissue.

24 Healing Case 5 For comparison, shown with the contralateral bones: A similar process occurring in a fractured rib

25 Healing Case 5 What process does this represent? Bone fracture and healing What name is used for the nodular structures that span the fracture ends? Callus Represents a late healing phase in fracture repair. With the non-union fracture the callus is larger and often less boney. This is because of movement of the fracture ends during healing

26 Healing Case 5 Morphologic Diagnosis? Left Femur: Distal physeal fracture, nonunion, chronic with (boney) callus formation

27 Inflammation Case 6 Spleen and bone from a chicken

28 Inflammation Case 6 Description? The spleen is markedly enlarged, misshapen and contains multifocal to coalescing, 1 3 mm, yellow nodules that extend into the parenchyma on cut surface replacing most of the normal architecture.

29 Inflammation Case 6 Description? Similar nodules are scattered throughout the bone.

30 Inflammation Case 6 Morphologic Diagnosis? Disease Name: Avian tuberculosis Etiology: Mycobacterium avium Splenitis and osteomyelitis, granulomatous, multifocal to coalescing, chronic, severe

31 Healing Case 7 Liver from an 8 year old dog Chronic vomiting, inappetence, Icterus

32 Healing Case 7 Description? The liver is firm and the normal architecture is replaced by numerous, coalescing, pale yellow nodules, ranging in size from ~0.2 to 2 cm in diameter Bands of fibrous connective tissue and residual hepatic parenchyma separate the nodules

33 Healing Case 7 Morphologic Diagnosis? Hepatic fibrosis and regenerative nodular hepatocellular hyperplasia, diffuse, chronic, severe

34 Healing Case 7 Morphologic Diagnosis? or Cirrhosis (end-stage liver)!

35 Healing Case 7 What process does this represent? Healing and scarring a combination of fibrosis and regeneration (unsuccessful ) The liver is composed of quiescent cells which have some capacity to heal via regeneration

36 Healing Case 7 Compare cirrhosis with hepatic neoplasia.. Cirrhosis Malignant hepatic neoplasia Decreased organ size! Overall firm texture Very little necrosis Well defined nodules Often overall increased organ size! Texture varies Necrosis often causes umbilication Often masses are illdefined and invasive

37 Stumpy the raccoon Healing Case 8

38 Description? Healing Case 8 The distal extremities, including all of the paws, the tail, the ears and the nose are absent. Covering the affected regions is pink to pigmented hairless tissue with a sharp line of demarcation separating these areas from the normal adjacent skin.

39 Healing Case 8 What is the name of the tissue covering the severed/ absent extremities? Granulation tissue and fibrous connective tissue (fibrosis)

40 Healing Case 8 What is the name of the tissue covering the severed/ absent extremities? Granulation tissue and fibrous connective tissue (fibrosis) Granulation tissue histology: Necrotic debris/fibrin on surface Streams of fibroblasts parallel with the skin surface Intersected by small capillaries Loose infiltrates of inflammatory cells (macrophages especially) Another example

41 Healing Case 8 Another example of healing by scarring (repair by firbrosis) Rumen scars representing previous regions of ulceration. The rumen and skin are lined by constantly dividing cells (labile cells) and can heal by regeneration, but if damage is sufficiently severe, scarring will occur

42 Questions?