INTERPRETATION OF H&E STAINING 1:

CELL INJURY AND INFLAMMATION

SCPA 603- Histopathological Techniques for Routine and Research

Somphong narkpinit, M.D. Department of Pathobiology Faculty of Science Mahidol University

somphong.nar@mahidol.ac.th

Interpretation of H&E staining 1:

CELL INJURY

Stages in the cellular response

Reversible and Irreversible Cell Injury

Reversible cellular changes & accumulations

Hydropic degeneration (hydropic change)

- Only the cytoplasm is involved

- Water accumulates & the cell swells

- Large vacuoles in the cytoplasm

- Light microscopy

- Cytoplasm is pink & granular

- Electron microscopy (ultrastructural)

- Organelles are swollen

- Ribosomes displaced

- Lysosomal activity very apparent

Intracellular Accumulations

Intracellular accumulation of abnormal amounts of various substances.

(1) a normal cellular constituent accumulated in excess, such as water, lipids, proteins, and carbohydrates

(2) an abnormal substance, either exogenous, such as a mineral or products of infectious agents, or endogenous, such as a product of abnormal synthesis or metabolism

(3) a pigment.

Reversible cellular changes & accumulation

Hyaline change

- Homogenous , glassy , eosinophilic appearance in H&E

stained tissue sections

- Caused most often by nonspecific accumulations of proteinaceous material

- Ex. Glomeruli tufts in diabetic glomerulosclerosis

Reversible cellular changes & accumulations

Accumulation of exogenous pigments

- Naturally colored substances not requiring tissue stain to be seen

1 - Pulmonary accumulations of carbon , silica & iron dust

2 - Plumbism ( lead poisoning)

3 - Algeria ( silver poisoning)

- May cause a permanent gray discoloration of the skin & conjunctiva

Accumulation of endogenous pigments

- Melanin :

- Most common ; brown pigment

- Formed from tyrosine via tyrosinase

- Synthesized in melanosomes of melanocytes within

the basement membrane of the epidermis &

choroid of the eye.

- Transferred by melanocytes to adjacent clusters of

keratinocytes & macrophages (melanophores) in

the subjacent dermis

- Seen also in neoplasm

- Ex. Melanocytic nevus, melanotic macule

- Ex. Melanoma

- Bilirubin

- Catabolic product of the heme of hemoglobin &

myoglobin

- In pathologic conditions , accumulates & stains the blood,

sclera, mucosa , & internal organs producing a yellow

discoloration ( jaundice)

- Hemolytic jaundice

- Destruction of red blood cells.

- Obstructive jaundice

- intra or extrahepatic obstruction of the biliary tract.

- Hepatocellular jaundice Ex. Parenchyma liver damage

- Hemosiderin

- Iron – containing pigment , aggregates of ferritin

- In tissue appears as golden – brown amorphous

aggregates.

- Prussian blue dye – positive blue color stain

reaction.

- Exists normally in small amounts as physiologic

iron stores within tissue macrophages of the bone

marrow, liver, & spleen.

Hemosiderin Melanin

Lipofuscin

- yellowish to light brown, fat-soluble pigment; end

product of membrane lipid peroxidation

- “Wear & tear” pigment

- Commonly accumulates in elderly patients

- Found most often within hepatocytes &

at the poles of nuclei of myocardial cells.

Brown atrophy :

- accumulation of lipofuscin & atrophy of organs

Cardiac muscle Liver

NECROSIS

• There is denaturation of intracellular proteins and enzymatic digestion of the cell.

• The enzymes are derived either from the lysosomes of the dead cells themselves, in which case the enzymatic digestion is referred to as autolysis, or from the lysosomes of immigrant leukocytes, during inflammatory reactions.

Nuclear changes in necrotic cells:

• Karyolysis-basophilia of chromatin may fade.

• Pyknosis-nuclear shrinkage and increased basophilia.

• Karyorrhexis-nuclear fragmentation.

• Disappearance of nucleus.

Normal cell

Reversible cell injury with cytoplasmic & organelle swelling, blebbing & ribosome detachment Irreversible cell

injury with rupture of membrane & organelles, & nuclear pyknosis

Karyorrhexis Karyolysis

Morphology of necrosis.

Necrotic cells show

• increased eosinophilia with a glassy homogeneous appearance.

• The cytoplasm becomes vacuolated and appears moth-eaten.

• Finally, calcification of the dead cells may occur.

Necrosis

• Definition

• Death of groups of contiguous cells in tissue or organ

• Patterns

• Coagulative

• Liquefactive

• Caseous

• Fat necrosis

• Gangrene

Coagulative necrosis

Necrosis Normal

Coagulative necrosis

Liquefactive necrosis

Caseous necrosis

Caseous necrosis

Fat necrosis

Fibrinoid necrosis

Special form of necrosis, visible by light microscopy

Fibrin-like--- in immune reactions

Gangrenous necrosis

Apoptosis

•Programmed cell death.

•Noxious stimuli that damage DNA result in nuclear dissolution without complete loss of cell membrane integrity.

•Can be physiologic or pathologic.

Apoptosis - pathological

Graft-versus-host disease in colonic mucosa

Interpretation of H&E staining 1:

INFLAMMATION

41

Morphological classification of acute inflammation

Based on the exudate

Serous Fibrinous Purulent

Hemorrhagic Gangrenous

Patterns of Inflammation Serous Inflammation

Marked by outpouring of thin fluid

From blood serum, e.g. burn blisters

Effusion from mesothelial cells lining the pleural, peritoneal and pericardial cavity

Fibrinous Inflammation

A feature of pericardial and peritoneal inflammation

Vascular permeability allows larger molecules like fibrin to pass or procoagulant stimulus exists in the interstitium (e.g. cancer cells)

Suppurative Inflammation

Characterized by production of large amount of pus composed of neutrophils, necrotic cells and edema fluid

Involves pyogenic bacteria e.g. Streptococci and Staphylococcus aureus

Abscesses are focal localized collections of purulent inflammatory tissue caused by suppuration.

Ulcers

Local defect or excavation of the surface of an organ or tissue by sloughing of inflammatory necrotic tissue

Acute stage - intense polymorphonuclear infiltration and vascular dilation in margin

Chronic stage - margin and base develop fibroblastic proliferation, scarring and accumulation of lymphocytes, plasma cells and macrophages

Morphologic Patterns of Acute Inflammation

FIBRINOUS INFLAMMATION

A fibrinous exudate is characteristic of inflammation in the lining

of body cavities, such as the meninges, pericardium and pleura

Purulent inflammation

Characteristics

fibrin and neutrophil-rich exudate abscess: demarcated pus in tissue phlegmone: pus spreading in tissue empyema: pus in a body cavity

Examples purulent meningitis pneumonia (fibrinopurulent) erysipelas (S. pyogenes) purulent pyelonephritis

Brain Abscess

Localized liquefactive necrosis liver abscess

Removal of the dead tissue leaves behind a scar

Hemorrhagic inflammation Characteristics

large amount of blood in exudate

Examples haemorrhagic cystitis: BK cystitis, cyclophosphamide

plague: Yersinia pestis (G-negative), rats disseminate

bubonic plague: lymph node enlargement, lung plague: hemorrhagic pneumonia anthrax: Bacillus anthracis (G-pozitíi)e, bioterrorism! skin anthrax - ulcer sepsis; lung anthrax - hemorrhagic pneumonia uremic pericarditis

Gangrenous inflammation

Characteristics

purulent inflammation + ischemic necrosis

Outcome of acute inflammation

Full recovery

minimal tissue necrosis/exudate tissue capable of regeneration minimal organisation and scar Scarring

significant necrosis or exudate limited regeneration capability fibrosis/sclerosis - connective tissue accumulation

Persistent inflammation chronic inflammation

mononuclear inflammatory cells granulation tissue and fibrosis active chronic inflammation - neutrophils and chronic inflammation

Reparation

• tissue necrosis (eg. infarct)

• neutrophil granulocytes (acute inflammation, 18-20 hours) • macrophages (24-48 hours) (matrix metalloproteases, others) • fibroblast-activation (TGFβ, PDGF) • fibrosis -scar (weeks)

granulation tissue: fibroblasts, macrophages, angiogenesis

Scarring

Callus pleurae

fibrous pleuritis pleural fibrosis

Cirrhosis pseudolobular scarring Ito-cell activation

Acquired valve disease chronic endocarditis scarring after previous inflammation

Chronic inflammation

General characteristics Examples Granuloma

causes definitions chronic gastritis

cells of chronic mechanism rheumatoid arthritis

inflammation types

mediators of chronic inflammation

Chronic inflammation

Characteristics

prolonged (weeks/months) inflammation mononuclear inflammatory cells reparation non-specific / specific

Causes

prolonged acute inflammation autoimmune inflammation viral infection

difficult to degrade foreign materials

MORPHOLOGIC FEATURES OF CHRONIC

INFLAMMATION

1. Infiltration with mononuclear cells include Macrophages

Lymphocytes

Plasma cells

Eosinophils

2. Tissue destruction induced by the persistent offending agent or by the

inflammatory cells.

3. Healing by connective tissue replacement of damaged tissue,

accomplished by proliferation of small blood vessels (angiogenesis) and, in particular, fibrosis

Granuloma Definition

circumscribed chronic inflammation with many, activated macrohages

Causes

material degradable Tuberculosis Fungal infection Unknown

TH1 immune response (type IV hypersensitivity) - caseous necrosis

foreign body Langhans Touton type giant cell type giant cell type giant cell

Granuloma types, examples

Non-immune granuloma Lipogranuloma Foreign-body granuloma

Xanthogranulomatous inflammation Necrobiosis (NL, GA, RN)

Immune granuloma Tuberculosis Leprosy Syphilis Cat scratch disease

Fungal infection (Histoplasma, Cryptococcus, etc.)

Unknown pathomechanism Sarcoidosis

Disease Cause Tissue Reaction

Tuberculosis

Mycobacterium tuberculosis

Noncaseating tubercle Caseating tubercles

Leprosy

Mycobacterium leprae

Acid-fast bacilli in macrophages; noncaseating granulomas

Syphilis Treponema pallidum

Gumma: wall of histiocytes; plasma cell

Cat-scratch disease

Gram-negative bacillus

Rounded or stellate granuloma

Sarcoidosis

Unknown etiology

Noncaseating granulomas

Crohn disease Immune reaction against intestinal bacterial

dense chronic inflammatory infiltrate with noncaseating granulomas

Examples of Diseases with Granulomatous Inflammations