Histopathology Flashcards
What are the layers of the epidermis
(superficial to deep)
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
Basement membrane
What cells make up the epidermis
Keratinocytes
What is contained within the dermis
Collagen
Elastin
Glands
Vascular supply
What does hyperkeratosis mean
Increase in size of stratum corneum
Increased keratin
What does parakeratosis mean
Increased nuclei in the stratum corneum
They get retained there
What does acanthosis mean
Increase in the stratum spinosum
What does acantholysis mean
Reduced cohesions between keratinocytes
What is spongiosis
Intercellular oedema
What does actinic mean
Damaged by the sun
What is a benign derm neoplasm
Seborrheic Keratosis
What do seborrheic keratoses appear like
Rough pigmented plaques
Waxy and stuck on
Coin shaped
Who do seborrheic keratoses appear in
Middle age and elderly
What is the histology of seborrheic keratoses
Horn cysts
Orderly hyper-proliferation of epidermis
What are horn cysts seen in
Seborrheic keratosis
What are the premalignant derm neoplasms
Actinic keratosis
Keratoacanthoma
Bowens disease
How do actinic keratoses appear
Papule or plaque
Skin is red
White or yellow scaly crusts
What skin pathology is described as sandpaper like texture
Actinic keratosis
Histology of actinic keratosis
SPAIN
Solar elastosis
Parakeratosis
Atypia/dysplasia
Inflammation
Not full thickness
How does a keratoacanthoma appear
Dome shaped nodule with necrotic crusted centre
Histology of squamous cell carcinoma
Full thickness atypia/dysplasia throughout the epidermis spreading through basement membrane into dermis
Nuclear crowding
Histology difference between bowens disease and squamous cell carcinoma
SCC is bowens but it spreads through the basement membrane
How does bowens disease appear
Intra-epidermal squamous cell carcinoma
Flat
Red
Scaly patches
Stand alone
What are 2 precursors to SCC
Bowens disease
Actinic keratosis
Difference between actinic keratosis and bowens disease
Bowens disease is full thickness
How do basal cell carcinomas appear
Pearly surface
Telengiectasia
What is rodent ulcer
Basal cell carcinoma
Histology of BCC
Mass of basal cells pushing down into dermis
Palisading (alignment of nuclei in outermost layer)
Pathophysiology of amyloidosis
Excess proteins clumpb together to form beta sheets which make up fibrils
These then deposit in the EC space of tissues and cause damage
Why is AL amyloidosis called AL
Amyloid ‘light’- as excess light chains
What is a dyscrasia
Non specific term for disorder of blood
What is pathophysiology of AA amyloidosis
In chronic systemic inflammatory responses to infections, cancers and autoimmue conditions there is an excess of serum amyloid A which forms amyloid deposits in tissues
What is amyloid protein in AA amyloid
Serum amyloid A
What conditions cause AA amyloidosis
Infections- TB, osteomyelitis, IVDU skin infections, familial mediterranean fever
Autoimmine- IBD, RA, Ank spond
Cancer- Hodgkins lymphoma, Renal cell carcinoma
What is the most common form of familial amyloidosis
Familial mediterranean fever
Where is the amyloid deposition predominant in famial mediterranean fever
Kidney
Who does haemodialysis associated amyloidosis occur in
Chronic renal failure patients who are on especially peritoneal dialysis
What is the protein deposited in haemodialysis associated amyloidosis
Beta-2-microglobulin
What is most common presentation of amyloidosis
Nephrotic syndrome
Clinical features of amyloidosis
Carpal tunnel syndrome
Macroglossia
Hepatosplenomegaly
Restrictive cardiomyopathy
Nephrotic syndrome
Stain done for amyloidosis
Congo red stain under polarised light
Positive amyloid finding on congo red stain
Apple green birefringence- caused by beta pleated sheet configuration
What is negative congo red stain colour
Pink/red
When are neutrophils involved
Acute inflammation
When are macrophages involved
Late acute inflammation
Chronic inflammation like in granulomas
When are lymphocytes involved
Chronic inflammation
Lymphomas
When are plasma cells involved
Chronic inflammation
Myeloma
When are eosinophils involved
Allergic reactions
Parasitic infections
Hodgkins disease
When are mast cells involved
Allergic reactions
How do mast cells appear on histology
Lots of granules
Typical histological features of squamous cell carcinomas (not skin)
Keratin production
Intercellular bridges
Do not form glands
How do adenocarcinomas appear histologically
Form glandular epithelium
Form glands that can secrete substances
How do transitional cell carcinomas appear
Stretchy epithelium
Where do you get stretchy epithelium
Transitional cell carcinomas
What is the definition of histochemical stain
Result from the chemical reaction between stain and the tissue
What is the definition of immunohisto stain
Involves the antibodies against a specific antigen
What is lichenification
When skin becomes leathery and thick
What happens to skin if chronic atopic dermatitis
Lichenification
Acute histology of dermatitis
Spongiosis
Inflammatory infiltrate in the dermis (neutophils)
Dilated dermal capillaries
Chronic dermatitis histology
Acanthosis
Crusting
Hyperparakeratosis
T cells and eosinophil infiltrate
What is pathophysiology of seborrheic dermatitis
Inflammatory reaction to yeast infection- malassezia
What type of hypersentivity reaction is stevens johnsons syndrome
IV
What is the pathophysiology of SJS
Hypersensitivity reaction against the epidermis and mucosa which leads to necrosis of skin which can be wiped off
What determines if SJS or toxic epidermal necrolysis
<10% in SJS
>30% in TEN
What can cause SJS
Drugs- sulfonamides, carbamezapine
Infection- CMV, mycoplasma
How does chronic plaque psoriasis appear
Salmon pink well demarcated red plaques with silver scales
Where does chronic plaque psoriasis appear
Extensors of knees, elbows and scalp
What is auspitz sign
Rubbing plaque leads to pinpoint bleeding
What is the koebner phenomenam
Lesions form at site of trauma- seen in psoriasis
Histopathology of psoriasis
Parakeratosis
Loss of granular layer
Clubbing of rete ridges giving test tubes in rack appearance
Munros abscesses
Dilated blood vessels
Clubbing of rete ridges giving test tubes in rack
Psoriasis
What is pathophysiology of psoriasis
Type IV hypersensitivity reaction
When does guttate psoriasis present
Childhood
What triggers guttate psoriasis
Post strep throat 2 weeks ago
Typically in children
How does guttate psoriasis appear
Small spots
Rain drop plaque distribution
Over trunk and limbs
What is erythodermic psoriasis
Widespread disease with systemic symptoms
Where does pustular psoriasis affect
Hands and feet
How does pustular psoriasis appear
Red skin with white elevations of pus
What are the nail changes seen in psoriasis
Pitting
Onycholysis
Subungal hyperkeratosis
Who does flexural psoriasis occur in
Elderly
Where does flexural psoriasis occur
Creases in the skin
Groin
Submammary
Natal cleft
Histopathology of sarcoidosis
Non-caseating granulomas
Schaumann and asteroid bodies
CD4+
What are schaumann and asteroid bodies
Inclusions of protein and calcium
Blood findings of sarcoid
Hypercalcaemia
High ACE
High ESR
Anaemia
Leukopaenia
Skin findings in sarcoid
Erythema nodosum
Lupus pernio
Skin nodules
Eye manifestations of sarcoid
Anterior Uveitis
Posterior uveitis
Uveoparotid fever
Keratojunctivitis
Lacrimal gland enlargement
What happens in uveoparotid fever (heerfordt syndrome)
Bilateral uveitis
Parotid enlargement
Potentially facial nerve palsy
Joint manifestation of sarcoid
Arthritis
Bone cysts
Heart presentation of sarcoid
Cardiomyopathy
Conduction problems
Valvular disease
Pericarditis
What is the pathophysiology of bullous pemphigoid
IgG abs bind to hemidesmosomes which anchor epidermis to basement membrane
Leads to detachment of epidermis and formation of SUBdermal bullae
What is the pathophysiology of pemhigus vulgaris
IgG binds to desmoglein 1&3 which connect keratinocyes and between mucous membranes
Leads to breaking between layers of epidermis causing INTRAdermal bullae
What is difference in bullae between pemphigus vulgaris and bullous pemphigoid
Bullae in bullous pemphigoid are tense on erythematous base- DO NOT rupture
Bullae in pemphigus vulagris are easily ruptured which leads to a raw red surface
Nikolsky positive in pemphigus vulgaris
Histopathology of bullous pemphigoid
Subepidermal bulla with eosinophils
Linear deposition of IgG along basement membrane
Histopathology of pemphigus vulgaris
Acantholysis
Intradermal bulla
Netlike pattern of IgG
Complement deposition
What is the pathophysiology of dermatitis herpetiformis
IgA binds to basement membrane forming subepidermal bulla
What is dermatitis herpetiformis associated with
Coeliac
How does dermatitis herpetiformis appear
Itchy vesicles on extensors of elbows
Buttocks
Histology of dermatitis herpetiformis
Microabscesses which coalesce to form subepidermal bullae
Neutrophil and IgA deposits at tips of dermal papillae
How do lichen planus plaques appear
Hyperpigmented
Itchy
Polygonal
Papules
Plaques
Fine white network on the surface called wickams striae
Where is lichen planus normally found
Inner surface of wrists
Oral mucous membranes with lacy appearance
Histopathology of lichen planus
Hyperkeratosis
Saw toothing of rete ridges
Basal cell degeneration
What are wickhams striae
White network on top of plaques seen in lichen planus
What are annular target lesions seen in
Erythema multiforme
Where are erythema multiforme lesions seen
Extensor surfaces of hands and feet
How do erythema multiforme lesions develop
Can become pleomorophic so are anything from macules, papules, petechiae and bullae
Causes of erythema multiforme
Infections- HSV, mycoplasma
Drugs- SNAPP
SNAPP causes of erythema multiforme
Sulphonamides
NSAIDS
Allopurinol
Penicillin
Phenytoin
What causes pityriasis rosea
Appears after viral illness
Development of pityriasis rosea
Salmon pink rash apppears first called herald patch
Oval macules in xmas tree distribution then appear
What is a herald patch
Erythematous patch with white centre seen in pityriasis rosea
What is the scientific word for moles
Melanocytic naevi
Histology of melanomas
Atypical melanocytes
Initially radial growth phase then vertical phase
Buckshot appearance in vertical phase
Steps of atherogenesis
Endothelial injury
LDL enters subintimal space and gets trapped
LDL oxidised
Oxidised LDL gets taken up by macrophages via scavenger receptors becoming foam cells
Foam cells apoptose which causes cholesterol core
Increase in adhesion molecules on endothelium results in more macrophages and t cells
Vascular smooth cells form fibrous cap
What receptors take up oxidised LDL into macrophages
Scavenger
Why is abdo aorta more affected by atherosclerosis
Around the origins of major branches there is turbulent blood flow which has a low oscillatory shear stress
What are ostia
Origins of major arteries
Which blood flow is anti-atherogenic
Laminar
Turbulent is atherogenic
How long of severe iscahemia causes myocyte death
20-40 mins
Complications of an MI
DARTH VADER
D-death
A- arrythmia
R- rupture
T- tamponade
H- HF
V- valve disease
A- aneurysm of ventricle
D- dresslers syndrome
E- embolism
R- recurrence
What can rupture most MI
Due to necrosis:
- Septum causing left to right shift or VSD
- Papillary muscle causing MR
- Ventricular wall causing haemopericardium
What valve disease is common post MI
Mitral regurgitation from papillary muscle rupture or necrosis
What causes persistent ST elevation post MI
Ventricular aneurysm which can develop for over a month after
Difference between pericardial effusion and tamponade
Tamponade is when the fluid obstructs the contractility of the heart
What causes fibrinous pericarditis post MI
If MI extends to the epicardium
Pericardial complications of MI
Fibrinous pericarditis
Dresslers
Effusion/tamponade
Early infarct associated pericarditis
What is a mural thrombus
Clot that sticks to wall of heart
When are mural thrombi common
Ventricular aneurysm
What is nutmeg liver
The appearance of the liver due to chronic hepatic vein congestion
Long term what does nutmeg liver become
Cirrhosis aka cardiac cirrhosis
What are haemosedirin laden macrophages
Macrophages which have taken onto red blood cells in lungs after alveolar have burst
AKA heart failure cells
Histology post MI
- under 6 hours
- 6-24 hours
- 1-4 days
- 5-10 days
- 1-2wks
- weeks-months
- Normal by histology, CK also normal
- Loss of nuclei, necrotic cell death, homogenous cytoplasm
- Infiltration of polymorphs then macrophages
- removal of debris
- granulation tissue, new blood vessels, collagen synthesis, myofibroblasts
- decullarising scar tissue
Histology of heart in HF
Dilated heart with thin walls
Haemosiderin macrophages in lungs
Scarring
Fibrosis and replaced myocardium
Pathophysiology of rheumatic fever
Cell mediated immunity and antibodies to strep antigens cross react with myocardial antigens
Histology of rheumatic fever
Beady fibrous vegetations
Aschkoff bodies
Anitschow myocytes
Treatment for rheumatic fever
Benzylpenicillin
Diagnosis of rheumatic fever
Jones criteria
Group A strep infection and 2 major criteria
Group A strep infection and 1 major+ 2 minor
Major jones criteria
Carditis
Arthritis
Sydenhams chorea
Erythema marginatum
Subcut nodules
Minor jones criteria
Fever
Raised ESR or CRP
Migratory arthralgia
Malaise
Tachycardia
Prolonged PR interval
History of rheum fever
How does rheum fever affect the following
- heart
- joints
- CNS
- skin
- endocarditis, pericarditis, mycocarditis
- arthritis, synovitis
- subcut nodules, erythema marginatum
- encephalopathy, sydenhams chorea
What is most common form of prostate cancer in over 50s
Adenocarcinoma
What is normal precursor of prostate cancers
Prostatic intraepithelial neoplasia
PIN
How is prostate cancer graded
Gleason
Rfs for RCC
Smoking
HTN
Obesity
Long term dialysis
Unopposed oestrogen
Heavy metals
3 types of malignant renal cancer
Renal cell carcinoma
Nephroblastoma
Transitional cell carcinoma
What group of people are nephroblastomas seen in
Childhood- is second most common childhood malignancy
Where do transitional cell carcinomas develop
Anywhere in urothelial tract- can be from renal pelvis to urethra
Most commonly in bladder
What are the types of renal cell carcinoma
Clear cell 70%
Papillary 15%
Chromophobe 5%
Difference in macroscopic appearance of renal cell carcinomas
Clear cell- golden yellow with haemorrhagic areas
Papillary- friable brown
Chromophobe- solid brown
Microscopic appearance of clear cell RCC
Nests of epithelium with clear cytoplasm
Microscopic appearance of papillary RCC
Papillary tubopapillary growth patter over 5mm
Microscopic appearance of chromophobe RCC
Sheets of large cells with distinct cell borders
Where do RCC appear from
Typically epithelial cells in the cortex of kidney
Microscopic appearance of nephroblastoma
Small round blue cells
Types of renal transitional cell carcinomas
Non-invasive papillary
Infiltrating urothelial carcinoma
Flat urothelial carcinoma in situ
How do non-invasive papillary urothelial carcinomas appear macroscopically
Frond like growths projecting from the walls
Often multifocal
How do non-invasive papillary urothelial carcinomas appear microscopically
The fronds which project are lined with urothelium
How do invasive urothelial carcinomas appear
Solid tumours stuck to pelvis
What are the 3 bladder tumours
Transitional cell 90%
Squamous cell carcinoma
Adenocarcinoma
What causes bladder squamous cell carcinomas
Schistomiasis
What causes bladder adenocarcinomas
Arise from intestinal metaplasia or urachal remnants
Location of the lung cancers
Proximal bronchi- small cell and squamous
Distal- adenocarcinoma
Histology of squamous cell lung cancer
Keratinisation
Intercellular prickles
Which lung cancer is associated with hypercalcaemia
Squamous cell carcinoma
PTHrp secretion
Histology of adenocarcinomas lung
G;andular differentiation- gland formation and mucin production
Which paraneoplastic syndromes are small cell carcinoma are associated with
SIADH
Cushing from ACTH
Lambert eaton
What cells does small cell lung cacner arise from
Neuroendocrine
Which lung cancers have high relationship to smoking
The S’s
Histology of small cell carcinoma
Small
Poorly differentiated
Oat cells
Histology of large cell carcinoma
Poorly differentiated
Large cells
Large nuclei
Prominent nucleoli
No glandular or squamous differentiation
How are tumours staged
TNM
Tumour- invasion
Nodes- lymph nodes involved
Mets
What are the 3 benign renal tumours
Papillary adenoma
Oncocytoma
Angiomyolipoma
Where are the renal papillae
Where collecting ducts enters the ureters
What are papillary adenoma
Renal epithelial tumours with a papillary structure
Less than 5mm
What is an oncocytoma
Benign renal epithelial tumour characterised by presence of oncocytes- eosinophillic cytoplasm
What are angiomyolipomas made up of
Mesenchymal tumour
Fat
Blood vessels
Muscle
What renal cell carcinoma is common in dialysis associated cystic disease
Papillary carcinoma
Management of nephroblastoma
Nephrectomy with pre or post op chemo
What is myocyte disarray seen in
HCM
Where does hypertrophy occur in HOCM
Interventricular septum
What is most common gene affected in HOCM
Beta myosin heavy chain
BMHC
Most common cause of restrictive CM
Amyloidosis
What is libmen sacks endocarditis
Cardiac complication of SLE and APL where get vegetations on endocardium
Characteristics of libmen sacks endocarditis vegetations
Warty vegetations that are sterile and platelet rich
Organisms which cause acute endocarditis
Staph aureus
Strep pyogenes
Organisms which cause sub-acute endocarditis
Strep viridans
Staph epidermis
HACEK
Coxiella
Mycoplasma
Candida
What organisms are in HACEK
Haemophilus
Aggregatibacter
Cardiobacterum
Eikenella
Kingella
Most common valvular problems in IE
Mitral and aortic regurg
Immune phenomena in IE
Roth spots- in eyes
Osler nodes- red painful nodes on hnads or feet
Haematuria from glomerulonephritis
Thromboembolic complications of IE
Janeway lesions
Septic abscesses
Microemboli
Splinter haemorrhages
Splenomegaly
How is IE diagnosed
Dukes criteria
- 2 major
- 1 major and 3 minor
- 5 minor
Major dukes criteria
Positive blood culture growing typical IE organism
Vegetations on echo/new regurg murmur
Minor dukes criteria
Risk factor
Fever
Thromboembolic phenomena
Immune phenomena
Positive blood cultures that dont meet major criteria
Tx for IE
Start broad spectrum abx then treat according to sensitivities
Abx for subacute IE
Benzylpenicillin and gentamycin
OR
Vancomycin
Abx for acute IE
Flucloxacillin for MSSA
Rifampicin, vancomycin and gentamicin for MRSA
What are 5 benign neoplastic breast conditions
Fibroadenoma- most common
Intraductal papilloma
Radial scar
Phyllodes tumour
Fibrocystic disease
What are fibroadenomas
Benign neoplasms of fibrous tissue and glandular tissue
What causes fibroadenomas to increase in size
Pregnancy as hormone responsive
Cytology of fibroadenoma
Branching sheets of epithelium in antler horn or honeycomb sheets
Bare nuclei and stroma
How do intraductal papillomas present
Bloody discharge or clear
Lump
Can be pain
Histology of intraductal papilloma
Papillary mass with a dilated duct lined by epithelia
What is a radial scar
A benign sclerosing lesion often found on histology
Called scar as what appears like under the microscope histologically
Histology of radial scar
Central fibrous stellate area
What are radial scars over 1 cm called
Complex sclerosing lesions
How does radial scar appear on mammography
Stellate area which can be confused for carcinoma
How do phyolldes tumours present
Palpable masses in over 50s
How does fibrocystic breast disease present
Lumpiness in breasts which changes according to cycle
Histology of fibrocystic breast disease
Fibrous tissue containing cysts with flattened and cuboidal epithelium
What are the breast proliferative cancers
A group of intraductal epithelial proliferations which are asymptomatic but can develop into a breast carcinoma
Usual epithelial hyperplasia
Flat epithelial atypia
In situ lobular neoplasia
What is the difference between the 3 breast proliferative conditions with regards to their histology
Usual type- growth of epithelial and glandular tissue protruding into lumen in fronds
Flat atypia- multiple layers forming a smaller but regular circular lumen
Intralobular neoplasia- solid proliferation of aplastic cells where can just see the lumen
What cancers does BRCA increase the risk of
Breast
Ovarian
Pancreatic
Prostate
Wht does pregnancy reduce the risk of breast cancer
There is differentiation of milk producing luminal cells which removes them from pool of potential cancer cells
What is pagets disease of the breast
Eczema of nipple then areola- never get eczema on nipple normally
What is the screening programme for breast cancer
47-73 year olds invited every 3 years for mammography
What is looked for on mammographyin breast cancer screening
Microcalcifications
What is difference in detection of lobular and ductal carcinoma in situ
Lobular- always on biopsy as no microcalcification
Ductal- appear as areas of microcalcifications on mammogram. Typically on screening unless get pagets
What do lobular breast carcinomas lack
Protein E-cadherin
Which breast cancer does pagets develop from
Ductal