Histopathology Flashcards
Cell that frequently divide to replace lost cells
Labile cells
not typically dividing to replace injured cells
Do not frequently go cell division
Only undergo replication to replace injured cells
Stable cells
Stable cells examples
Parenchymal cells of liver and kidneys
Cell class that do not undergo replication following maturation
Permanent Cell
Permanent cell example
neurons (nerve cell)
incomplete or defective development of tissue/organ. Shows no resemblance to the normal mature structure. Usually happens in paired organs (kidneys, gonads)
Aplasia
complete non-appearance of organ.
Agenesia
failure of tissue/organ to reach normal mature adult size
Hypoplasia
Failure of organ to form an opening
Example:
Imperforate anus (without opening)
Microtia - absence of ear canal
Atresia
Cellular adaptation mechanisms
Atrohpy
Hypertrophy
Hyperplasia
Metaplasia
Dysplasia
Anaplasia
acquired decrease in tissue or organ size
Atrophy
Atrophy that occurs as consequence of maturation
example:
Atrophy of thymus at puberty
Decrease in uterus size after childbirth
Physiologic
Pathologic atrophy:
occurs if blood supply becomes reduced or below the critical level (may develop as a result of pressure atrophy)
Vascular atrophy
Pathologic atrophy:
persistent pressure on the organ or tissue may directly injure the cell or may secondarily promote diminution of blood supply
Pressure atrophy
Pathology atrophy:
due to lack of hormones needed to maintain normal size and structure
Endocrine atrophy
Pathologic atrophy:
due to lack of nutritional supply to sustain normal growth
Hunger/Starvation atrophy
Pathologic atrophy:
too much workload can cause general wasting of tissues
Exhaustion atrophy
Pathologic atrophy:
Inactivity/diminished activity/functions
Atrophy of disuse
Increase in tissue/organ size due to an increase in size of cells making up the organ
Hypertrophy
hypertrophy of skeletal muscles due to frequent exercise
Physiologic hypertrophy
Hypertrophy of the myocardium (hypertension)
Aortic valve disease
Pathologic hypertrophy
Type of hypertrophy that may develop as response to a deficiency (usually in paired organs– when one is removed)
Compensatory
Example of compensatory hyperthrophy
Renal hypertrophy
Increase in tissue or organ size due to an increase in the number of the cells making up the organ (new cells are formed)
Hyperplasia
Hyperplasia:
Happens in response to the need increase in uterus, breast during pregnancy.
Increase in breast size during puberty (glandular stimulation)
Physiologic Hyperplasia
Type of hyperplasia:
Erythroid bone marrow hyperplasia in people in high altitude
Physiologic hyperplasia
Type of hyperplasia:
Grave’s disease - diffuse crowding of epithelial cells
Hyperplasia of endometrium due to excessive estrogen
TB of cervical lymph nodes - there is increase in the number of lymph nodules
Pathologic
Occur frequently together with hypertrophy and can be triggered by the same mechanism
Compensatory
Involves transformation of adult cell type into another adult type (reversible process)
Metaplasia
Mesenchymal metaplasia involves:
Connective tissues
Original tissue:
Ciliated columnar epithelium of bronchi
Stimulus: Cigarette smoking
Metaplastic tissue:
Squamous epithelium
Original tissue:
Transitional epithelium of bladder
Stimulus:
Trauma of bladder
Squamous epithelium
Original tissue: Columnar glandular epithelium
Stimulus: Vitamin A deficiency
Metaplastic tissue:
Squamous epithelial cells
Original tissue: Esophageal squamous
Stimulus: Gastric acidity (too much drinking coffee)
Metaplastic tissue:
Columnar epithelium
Dysplasia is also known as
atypical metaplasia
Pre-neoplastic lesion
Change in cell size, shape, and orientation (reversible).
May lead to cancer but not necessarily
Dysplasia (atypical metaplasia)
dedifferentiation (irreversible) transformation of adult cells into embryonic/fetal cells
anaplasia
Causes of cell injury
Anoxia - lack of oxygen supply
Infectious agents
Mechanical agents/Trauma
Chemical Agents - carcinogens (chloroform, benzene)
No.1 cause of cell injury
Oxygen deprivation
Hypoxic cell injury for neuron is irreversible after (minutes)
3-5 minutes
Hypoxic cell injury in myocardial cells and hepatocytes is irreversible after (time)
1-2 hours
Skeletal muscle hypoxic injury is irreversible after (time)
many hours
Appearance of affected organs in gross change
Organ pallor (pale), Increased weight
Earliest change of tissue is seen
Microscopically
First manifestation of cellular change
cellular swelling
Irreversible changes
Enzymatic digestion of cells
Protein denaturation
Cytoplasmic changes
Nuclear changes
Cytoplasmic changes includes
Increased eosinophilia (pink/orange)
Large cells “cloudy swelling”
Irreversible nuclear changes
Pyknosis
Karyolysis
Karyorrhexis
condensation of nucleus
pyknosis
fragmentation/segmentation of nucleus
Karyorrhexis
Physiologic cell death
Programmed cell death
Death of single cell in a cluster of cells
Apoptosis
Cell shrinkage - integrity of membrane remains intact
Cellular components do not leak out = no inflammation
Chief morphologic features:
Chromatin condensation
Chromatin fragmentation
Cell shrinkage
Cytoplasmic bleb formation
Phagocytosis of apoptotic cells
Apoptosis
Pathologic cell death
Accidental cell death
Cell swelling
Leakage of cellular components = Inflammation
Change in organ can be seen in gross
Necrosis
Type of Necrosis:
due to to sudden cut off of blood supply
Coagulative
Type of Necrosis:
Due to ischemia
Appears ghostly (cell outline is maintained)
Usually happens in solid organs (liver, kidneys, heart)
Microscopically cell outlines are preserved
On gross, affected organs somewhat firm, appearing like a boiled material
Actions of hydrolytic enzyme is blocked (normal cell death releases lysozyme - hydrolytic enzyme for cell self destruction)
I.e. Myocardial Infarct
Coagulative
Type of Necrosis:
On gross, affected organ appears liquefied, creamy yellow (increased pus)
Liquefactive
Type of Necrosis:
Softening of organs is due to actions of hydrolytic enzymes
Complete digestion of cells
i.e. brain infarct and supporative bacterial infections
Liquefactive
Type of Necrosis:
On gross, tissue organ appears greasy resembling “cheese”
Caseous
Type of Necrosis:
Combination of coagulative and liquefactive
Usually seen in TB
Microscopically it appears as amorphous granular debri surrounded by granulomatous inflammation
Caseous (cheeselike)
Type of Necrosis:
Seen in immune reactions of the blood vessel
Deposition of fibrin in vessel wall
Cannot be seen in gross examination
Can only be microscopically
Fibrinoid
Type of Necrosis:
Destruction of fat cells due to release of pancreatic lipases
Fat
Type of Necrosis:
Death of fat tissues due to loss of blood supply
On gross, appears chalky white
Microscope, infiltrates of foamy macrophage adjacent to adipose tissues
Seen in pancreatitis
Affected organ is usually breasts
Fat
Type of Necrosis:
necrosis secondary to a ischemia
Not a specific pattern of necrosis
Gangrenous
Type of Necrosis:
Refers to a limb that loss its blood supply in the lower extremities
Skin - dry, black, and is observed in various stages of decomposition
Gangrenous
due to venous occlusion, example of this is SUPPURATIVE BACTERIAL INFECTION
wet gangrene
due to arterial occlusion and example of this is FOOT EMBOLISM
Dry gangrene
Tissue reaction to injury
Inflammation
Goal of Inflammation:
1)To remove the initial cause of the injury
2)To remove the consequences of injury
Cardinal signs of inflammation
Dolor
Rubor
Calor
Tumor
Functio laesa
Cardinal sign of inflammation: pain
dolor
Cardinal sign of inflammation: redness due to increase blood flow
Rubor
Cardinal signs of inflammation: heat
Calor
Cardinal signs of inflammation: swelling
Tumor
Cardinal Signs of Inflammation: destruction of functioning units of the cell
Functio laesa
Type of inflammation:
rapid response to an injurious agent
acute inflammation
Hallmark sign of acute inflammation
Exudation: escape of fluid proteins, blood cells from the vascular system)
Edema: excess to fluid in interstitial tissues and cavities
escape of fluid proteins, blood cells from the vascular system)
Exudation
excess to fluid in interstitial tissues and cavities
Edema
Cellular infiltrate of acute inflammation
neutrophils
Prolonged duration of inflammation
Chronic inflammation
Cellular infiltrate of Chronic inflammation
Mononuclear cells (monocytes, macrophage, lymphocytes, plasma cells)
Resolution of inflammation
Healing
Healing stage:
No destruction of normal tissues
Offending agent is neutralized
Vessels return to their normal permeability state
Excess fluids is reabsorbed
Clearance of mediators and inflammatory cells
Simple resolution
Healing stages:
Resolution
Regeneration
Replacement by connective tissue scar
Replacement of loss or necrotic or tissues with a new tissue that is similar to those that were destroyed
Regeneration
Death of the entire body
Somatic Death
Changes that can be observed immediately after somatic death
Primary changes
Primary changes in somatic death
1)CNS/Nervous failure
2)Respiratory failure
3)Cardiac failure
Changes that can be noted/observed few hours after death
Secondary changes
cooling of the body after death
Algor mortis
Algor mortis happens at a rate of
7 degF/hour
Helps establish time of death
Faster in cooling in: cold weather, lean malnourished
Delayed cooling in infectious disease followed by increase in temperature
Algor mortis
stiffening of the body
Rigor mortis
Rigor mortis starts ___ following death
2-3 hours
Rigor mortis completes in ___
6-8 hours
Rigor mortis remains _____ hours and persists for ____ days
12-36 hours
3-4 days
Rigor mortis hasten stiffness in:
warm environment and in infants
Delay of rigor mortis:
cold temperature and obese individuals
Postmortem hemolysis
Livor motis
Purplish discoloration of skin
Sinking of fluid blood into capillaries of the dependent body parts
Livor mortis
Importance of livor mortis
determine if body position has changed at the scene of death
Occurs slowly or immediately after death
Post mortem clotting
due to the release of hydrolytic enzymes
autolysis
Rotting and decomposition by bacterial action
Putrefaction
Refers to the drying and wrinkling of cornea and anterior chamber
Dessication
Involves examination of a dead body
Autopsy/Necropsy
Main purpose of autopsy
determine cause of death
Important requirement to do autopsy
consent from the nearest kin
Types of autopsy as to purpose
1)Routine Hospital Autopsy
2)Medico Legal Autopsy - carried by govt. Agencies
Type of autopsy as to completeness of procedure:
1)Complete autopsy - from head to foot
2)Partial autopsy - examines the region of the body
Types as to manner of incision:
Y-shaped incision
Straight incision
Type of incision:
cadaver is opened from shoulders down from xiphoid area and incised down to pubis
Y-shaped incision
Incision done in adult cadaver
Y-shaped incision
Type of incision:
opened from the midline of the body from the suprasternal notch down to the pubis (for babies)
Straight cut
Autopsy technique:
organs are removed one by one
Rudolf Virchow
Autopsy technique:
Involves in-situ dissection (original place)
Carl Rokitansky
Autopsy Technique:
Involves en-bloc (by system) removal of organs
Anthon Ghon
Type of autopsy:
Organs are removed “en masses” - all at the same time
M. Letulle
Advantage: Quick and Suitable for beginners
Disadvantage: Causes loss of continuity
Virchow’s method
Advantages:
In infected bodies (HIV, Hepa B)
Considered good in children
Disadvantages:
Difficult to perform
Rokitansky
Cervico-thoracic, abdominal, pelvic organs are removed in three blocks
Neuronal system is removed as another block
Ghon’s method
Advantage: Excellent preservation
Handling organs easier
Disadvantage:
inter-relationships is difficult to study, if disease is extending to all blocks
Ghon’s method
Advantage: inter-relationships are preserved body can be handed over quickly
Disadvantage: Organs difficult to handle
Lettulle’s method
Process of tumor formation
Abnormal proliferation of cells
New cells are produced which are functionless compared to a normal cell
Neoplasia
Removal of tumor cells
Biopsy
Types of tumor
Benign
Malignant
Type of tumor
Slowly growing mass
Regular surface, capsulated, not attached to deep structures
Benign tumor
Type of tumor
Rapidly growing mass
Irregular surfaces, Non-capsulated attached to deep structures
Malignant tumor
Type of tumor
Noninvasive to another organ or tissue
No spread or metastasis
Benign tumor
Type of tumor
Invasive to other organs
Spread and metastasis
Malignant tumor
Type of tumor
Well differentiated
No recurrence after surgery
Benign tumor
Type of tumor
Poorly differentiated, moderately, or well differentiated
Recurrence after surgery
Malignant tumor
Type of tumor
No bleeding in cut surfaces
Named adding suffix -oma
Slight pressure effect on the neighboring organ
Benign tumor
Type of tumor
Bleeding from cut
Named by adding suffix sarcoma or carcinoma
Remarkable pressure effect on neighboring tissue
Malignant tumor
Gradings of tumor:
Different cells
normal cells
Gradings of tumor
abnormal cells
undifferentiated cells
Value of grading
Guide for treatment
Prognostic guide
Broder’s classification
Grade I
Differentiated cells: 100-75%
Undifferentiated cells: 0-25%
Broder’s Classification
Grade II
Differentiated cells: 75-50%
Undifferentiated cells: 25%-50%
Broder’s classification
Grade III
Differentiated cells: 50-25%
Undifferentiated cells: 50-75%
Broder’s classification
Grade IV
Differentiated cells: 25-0%
Undifferentiated cells: 75-100%
Tumors that are amenable to surgery (good prognosis)
Lower grade tumor
Tumors that requires radical treatment (chemotherapy, radiation) (poor prognosis)
High grade tumor
Used to determine the spread of cancer in a patient
Based on the size of primary lesions, extent of spread to regional lymph nodes and presence or absence of metastases
Staging of tumor
TMN Classification
T
N
M
T- size of tumor
N - No. of lymph nodes involved
M- Presence or absence of metastasis
Tumor:
Unable to assess primary tumor
Tx
Tumor:
There is no evidence of primary lesions
T0
Tumor:
There is no evidence of primary lesions
T0
Tumor:
Carcinoma in situ
Tis
Tumor:
Tuor penetrates submucosa and mucosa
T1
Tumor:
The tumor invades but fails to penetrate the muscle layer
T2
Tumor:
The tumor penetrates the subserosa
T3
Tumor:
Tumors penetrates deep into the peritoneum or other organs
T4
N: Lymph node
Unable to assess lymph node involvement
Nx
N Lymph node
No lymph node involvement
N0
N lymph node
There is metastasis in perirectal nodes around one to three
N1
N lymph nodes
There is metastasis of four or more perirectal nodes
N2
Metastasis
Unable to assess distant metastasis
Mx
Metastasis
There is no distant metastasis
M0
Metastasis
There is distant metastasis
M1
Stage IA
Tumor - Node - Metastasis - Grade
T1a, T1b
N0
M0
G1,2
Stage IB
Tumor - Node - Metastasis - Grade
T2a, N0, M0, G1,2
Stage IIA
Tumor - Node - Metastasis - Grade
T2b, N0, M0, G1, 2
Stage IIB
Tumor - Node - Metastasis - Grade
T1a, N0, M0, G3,4
Stage IIC
Tumor - Node - Metastasis - Grade
T2a, N0, M0, G3, 4
Stage III
Tumor - Node - Metastasis - Grade
T2b, N0, M0, G3,4
Stage IV
Tumor - Node - Metastasis - Grade
Any T, N1 (any N), M0 (M1), Any G
Tumor size
T-1
0-2 centimeters
Tumor Size
T2
2-5 centimeters
Tumor size
T3
> 5 centimeters
Tumor size:
T4
Tumor has broken through skin or attached to cell wall
Lymph node status
N-0
Surgeon can’t feel any nodes
Lymph nodes
N-1
Surgeon can feel swollen nodes
Lymph nodes
N-2
Nodes feel swollen and lumpy
Lymph node status
N3
Swollen nodes located near collarbone
Metastasis:
M-0
Tested nodes are cancer free
Metastasis
M1
Tested nodes show cancer cells or micrometastasis
Identification of tissue or cellular antigens or phenotypic markers (found in tissues)
Immunohistochemistry
Make use of antigen antibody reactions by directly labelling of the antibody or by means of secondary labelling method
Immunohistochemistry
Most commonly used antibody used in IHC
IgG
Antibodies produced by different cells
Can react with various epitopes (reacts with antibodies)
Polyclonal
Polyclonal antibody source
goats, pigs, sheep
laboratory animals
More specific antibodies produced from individual clones of plasma cells
Monoclonal
Produces one type of antibody can react only with one specific type of epitope
Monoclonal
Animal source of monoclonal antibodies
mice
To detect antigens, antibodies must be
labeled
Most common enzyme for antigen retrieval
Horse Radish Peroxidase
Color developer for labeling antibodies
chromogen
Most common method for antigen retrieval
Enzyme
Diamino benzedene (DAB) color
brown
AEC - 3-amino-9ethylcarbazole color
brick red
Traditional counterstain for enzyme
hematoxylin
Alternative phosphatase for horse radish peroxidase
alkaline phosphatase
Optimum incubation time to link antibody with enzyme peroxidase
60 mins at Room temperature
Fluorochrome label dye used for fluorescence microscope
FITC - Fluorescein isothiocyanate
Plant or animal proteins which can bind to tissue carbohydrate
Can also be used to detect antigens, can also be labelled like antibodies
Lectins
Cryostat frozen sections and fixed in a few seconds using
absolute methanol or acetone
Purpose of cryostat frozen sections
To prevent destruction of labile antigenic sites
To preserve position of antigens
Processed specimens (antigen retrieval) specimens
Formalin fixed
Paraffin embedded
Methods of antigen retrieval from processed tissues
1)Proteolytic enzyme retrieval (PIER)
2)Microwave antigen retrieval/ Heat Induced Epitope retrieval
3)Pressure cooking antigen retrieval
4)Autoclave heating
5)Waterbath heating
6)Steamer heating
7)Decloaker heating
8)Combination of microwave and enzyme digestion
Commonly used enzyme in proteolytic enzyme retrieval
trypsin and protease
Microwave antigen retrieval/ Heat Induced Epitope retrieval duration
20 minutes
Waterbath heating temperature
90 deg C or 95-98 deg C
control:
tissue section with antigen being detected
positive
Control:
omit primary antibody from the staining schedule
negative
Internal tissue control a.k.a
built in control
Internal tissue control contains
target antigen
dissolution of nucleus
karyolysis