Skin Flashcards
(261 cards)
1
Q
What are the functions of skin?
A
Protection - from UV light chemical Burns mechanical insults bacterial and fungal
Sensation - from touch, pressure, pain and temperature
Thermoregulation - subcutaneous tissues and hairs maintain heat while sweat glands and increased blood flow maintain coolness
Metabolic - vitamin D3 synthesis from UV light adipose to stores triglycerides
Sexual attractant
Waterproofing and prevention of loss of water from the body
2
Q
What types of skin can people have
A
1- always burns, never tans, extremely sensitive to sun
2 - burns easily, tans a little, very sensitive to sun
3 - burns a little, always tans,
4 - rarely burns, tans well, relatively insensitive to sun
5 - never burns deeply, coloured, insensitive to sun
3
Q
What are the three main layers of skin?
A
Epidermis
Dermis
Subcutaneous tissue
4
Q
What are the five layers of the epidermis called?
A
Stratum corneum,
Stratum lucidium
Stratum granulosum
Stratun spinosum
Stratum basale
5
Q
What are the two layers of the dermis called?
A
Papillary dermis
Reticular dermis
6
Q
Give 10 of the structures within skin?
A
Hair shaft
Sebaceous gland
Hair follicle
Arector pili muscle
Lymphatics
Arteries
Veins
Nerves
Sweat glands (eccrine)
Rete ridges (downwards projections)
Dermal papillae (upwards projections)
Apocrine glands
7
Q
What type of epithelium is the skin made of?
A
Self regenerating stratified squamous epithelium
8
Q
What protein does the skin secrete for protection?
A
Keratin
9
Q
What causes the variation in skin pigmentation?
A
Melanin production not the number of melanocytes
10
Q
What is the stratum basale?
A
Basal layer of epidermis
Cuboidal or low columnar cells which connect the stratum spinosum to the basement membrane separating the epidermis and dermis
11
Q
What is the stratum basale responsible for?
A
Repeated mitotic division for regeneration
12
Q
What cells are in the stratum spinosum?
A
Keratinocytes with large pale nuclei and prominent nucleoli
13
Q
How do the cells appear in the stratum granulosum?
A
Cells become more flattened and contain basophilic granules
Towards the surface cells lose their nuclei and cytoplasm leaving masses of formed keratin
14
Q
What is the stratum lucidium and what is it function?
A
A very thin layer of cells seen in hands and feet
Provides additional protection
15
Q
How does the stratum corneum appear?
A
Composed of flat flakes and sheets of keratin coated with waterproof protection that is synthesized by the cells of the stratum granulosum
16
Q
Name three other cell types within the epidermis?
A
Melanocytes
Langerhans cells
Merkel cells
17
Q
What is the function of melanocytes?
A
To protect against sunlight
18
Q
What is the function of langerhans cells?
A
Recognise external antigens
19
Q
What is the function of Merkel cells?
A
Provide touch receptors
20
Q
What are rete ridges and what are their function?
A
Downward projections between the epidermis and dermis
Additional resistance to frictional shearing force by providing stronger tethering
Most developed on the soles of the feet and palms of the hands
21
Q
Where are melanocytes found and how do they appear?
A
Scattered cells in the basal layer
More numerous in areas exposed to the sun
Round cells
Clear cytoplasm
22
Q
What do melanocytes produce?
A
Melanin
23
Q
What are langerhans cells?
A
Antigen recognition and processing cells
24
Q
Where are langerhan cells found and how do they appear?
A
Present in all layers of the epidermis
Easily recognisable within the stratum spinosum and upper dermis
Pale staining
Irregularly lobulated nuclei
Almost clear cytoplasm
25
Where are Merkel cells found and how do they appear?
Intraepidermal touch receptors
Scanty in adult skin
Round cells
Pale staining cytoplasm
Round pale staining nuclei
Dense core granules in vesicles
26
What is the microscopic appearance of keratinocytes?
Low columnar cells with prominent nuclei and nucleoli
27
What cells does the dermis consists of?
Fibrocollagenous and elastic tissues which contain vessels, nerves and sensory receptors
28
What are the two parts of the dermis?
Below the rete ridges is the papillary dermis, deep to this is the reticular dermis
29
What is the papillary dermis made up of?
Loose tissue containing fine collagen type 3 and thicker elastin fibres
It also to contains arterioles, capillary loops, venues, lymphatics and fine nerves
30
What is the reticular dermis made of?
Course type 1 collagen, thicker elastin fibres which are both much larger than seen in the papillary dermis
31
What is the overall thickness of skin is determined by?
The thickness of the dermis and subcutaneous tissue
Eyelid these layers are shallow
Buttock these layers are thicker
32
What happens to the dermis with age and sun damage?
Collagen and elastin fibres in the upper dermis progressively degenerate so skin loses its texture and may wrinkle
33
What is the subcutaneous tissue?
The deepest layer of skin containing mainly adipose tissue and larger vessels
34
How is the adipose tissue arranged in subcutaneous tissue?
Compartmentalised by downward extensions of the dermal collagen
35
What is the function of subcutaneous tissue?
Shock absorber
Thermal insulator
Fat stores
36
What are the skin adnexal structures?
Hair follicles
Sebaceous glands
Eccrine glands
Apocrine glands
37
What is the function of hair follicles?
Produce hair shafts which are composed mainly of keratin
Thermoregulation
38
What is the process of hair shaft formation?
Hair follicle is cylindrical structure consisting of five concentric layers of epithelial cells. As they move towards the surface during maturation the inner 3 layers undergo keratinisation to form the hair shaft, the other 2 layers form and epidermal sheath
39
What are the two types of sebaceous glands?
Eccrine glands (sweat glands)
Apocrine glands
40
Where are the majority of the sebaceous glands situated?
Hair follicles - lying at the junction of the upper third of the hair follicle
41
What do sebaceous glands secrete?
Sebum - provides waterproofing
42
Where are the sebaceous glands not associated with hair follicles situated?
Areolae
Nipples
Labia minora
Eyelids
Buccal and labia mucosa
These open directly to the skin surface
43
Where are sweat glands located?
Widespread throughout the skin
Located at the junction between the dermis and subcutaneous tissue
44
What is the function of sweat glands?
Synthesize sweat
Deposit it on the skin surface
Evaporation of sweat reduces body temperature
45
How do sweat glands appear microscopically?
Large columnar or pyramidal cells with central oval nucleus
Duct cells are darker staining
Double layer of epithelial cells with microvilli lining the lumen
46
Where are apocrine glands located?
Confined to a few localized areas
Axilla
Areolae
Groin regions
47
Where is the secretary component of an apocrine gland found?
Lower dermis
Subcutaneous tissue
48
What is the function of apocrine glands?
Unknown
In animals it is for territory marking and sexual attractant
49
How does skin from the scalp differ from normal skin?
Dermis is broad
Abundant hair follicles and associated sebaceous glands
50
How is hair dealt with in the laboratory?
Hair must be plucked not cut
Specimen is not fixed
Study hair shaft anomalies or hair root
51
How do nails differ from normal skin?
Dense keretinised plate which rests on the nail bed of stratified squamous epithelium
Proximately the root and the bed extend deeply into the dermis
52
How are nails dealt with in the laboratory?
Submitted to detect fungi or cause of nail pigmentation
Nail is softened in phenol processed as normal
53
How is a suspected melanoma below the nail sampled?
Remove nail then exercise lesion
Coloration due to trauma will grow out naevi and melanomas will not
54
How do skin on palms and soles differ from normal skin?
They are glabrous
Epidemis is thick with a prominent stratum granulosum
Producing a thick layer of keratin
Elongated rete ridges
55
Why is the skin altered on the palms and soles?
Both subject to regular shearing and frictional forces - skin is modified to resist forces
56
What does glabous mean?
Completely devoid of hair and hair follicles
57
How did the eyelids on skin differ from normal skin?
Very thin
Often only small margins given for cosmetic reasons
A modified Moh's technique can be used if not treated as a wedge with skin on one side and conjunctiva on the opposite
58
How does the lip differ from normal skin
Maybe received as wedge with skin on one surface and mucosa on the opposite
In between lies vermillion
Mucosa is non- keratinising mucosa containing salivary glands
59
What is vermillion?
The transition zone on the lips between the two different types of tissue (skin and mucosa)
60
What is a pilonidial sinus?
One or more short tracks leading from an opening in the skin, in or near, the lift at the top of the buttocks
Contains hairs
Maybe come infected leading to a discharge of pus
61
How are pilonidal sinuses treated within the lab and who do they affect?
Serial vertical sections
All processed
Affects males young to middle aged
62
What is a skin shave and how are they dealt with in the laboratory?
Removal of surface layers with a knife
Used for benign conditions that often bleed or catch
Process in total
Count pieces
Measure
Describe outer surface
Ink margins
Bisect if more than five millimeters
63
What is a curette and cautery and how is it dealt within the laboratory?
A loop is used to scrape an area of interest
Diathermy to seal the injury site
Used for benign conditions
Count pieces
Measure
Describe outer surface
Ink margins
Bisect if more than five millimeters
Process all
Can be total or partial removal
64
What is a skin punch biopsy and how is it dealt with in the laboratory?
A cylindrical knife cuts out tissue
Can remove total or partial lesion
Never used for malignant melanoma unless a total excision
Removes 2-8 millimeter cylinder of tissue
Used for inflammatory and benign conditions
Measure
Describe
Ink margins
Bisect if more than five millimeters
Process all
Levels at sectioning
65
What is an incisional biopsy and how is it dealt within the laboratory?
Usually an elongated ellipse showing pathology and normal skin
Can be orientated
Used for inflammatory and benign/ malign lesions
Is diagnostic
Measure
Describe
Ink
Bisect longitudinaly if big enough
Process all
Cut levels
66
What is a skin excision?
Often ellipse, oval or rhomboid
Can be orientated
Ised for inflammatory, benign or malignant lesions
Depending on lesion and anatomical site can process all or partial
Involves complete removal of lesion plus small amount of margin
Measure
Describe
Ink slice
With or without LS of tips
Describe lesion and distance to margins
67
What is Moh's micrographic surgery?
Specialist technique with freezing of specimen
Allows for margin analysis until clear
Once clear no further excision is taken
Allows for complete removal of lesion with minimal margins
68
What are wide local excessions of skin and how are they dealt with in the laboratory?
Re-excision of a tumor site either as margins were involved or due to margins not being minimal distance in original specimen
Maybe orientated
Measure
Describe
Ink margins
Blocks taken to demonstrate any existing pathology or representative blocks
69
Why is immunofluorescence used for skin specimens?
Used for blistering diseases and some connective tissue disease
70
What special considerations are required when taking a skin for immunofluorescence?
A site of biopsy is important in dermatitis herpetiformis biopsy is taken from clinically normal skin in other disorders it is taken perilesionally
Biopsy must demonstrate the epidermal dermal Junction
Serum samples may also be tested for autoantibodies
Biopsies are sent on saline soaked gauze or Michel's transport medium
71
How are skins for immunofluorescence dealt with within the laboratory?
Frozen upon arrival
They can be punch biopsies or ellipses
Cut on a cryostat at four microns
Panel consists of H&E, Iga, Igg, IGM and C3
72
What common pathology can be seen on shaves and C+C?
Seborrheic keratosis
Actinic keratosis
Warts
Benign looking melanocitic naevi
Fibroepithelial polyps (skin tags)
Pyogenic granulomas
Neurofibroma
Basal cell carcinoma (BCC)
73
What common pathology can be seen on punches?
Actinic (solar) keratosis
Basal cell carcinoma
Inflammatory lesions
Benign melanocitic naevi
Small hemangioma
Alopecia
74
What would be in a generic skin description?
Describe shape of tissue
Presence of sutures
Measure specimen
Presence of lesion
If lesion pigmented/non-pigmented if pigmented is outlined well circumscribed/ fairly well circumscribed/irregular/asymmetrical is color lightly/mid/darkly pigmented
Variable/mottled/halo (dark or light)
If non-pigmented is the color gray/white/pale/cream
Is the appearance pearly/crusted/keratotic/ulcerated/central/induration/rolled border/roughened/perdunculated
Is lesion shape raised papule/nodule, flat macule/patch
Raised but flat (plaque)
Measure lesion
Ink margins
Inking guide
Block ID
75
What is a papule?
A raised lesion less than five millimeters in diameter
76
What is a nodule?
A raised lesion over five millimeters in diameter
77
What is a macule?
A flat lesion less than five millimeters in diameter
78
What is a patch?
A flat lesion over 5 mm in diameter
79
What is a plaque?
A lesion that is raised but has a flat top
80
What is a blister?
A fluid filled lesion that is less than five millimeters in diameter
81
What is a Bulla?
A fluid filled lesion more than five millimeters in diameter
82
When a clinician a sebaceous cyst what are they referring to?
Epidemoid or pillar cysts
83
What is an epidemoid cyst?
An intradermal lesion +/- open to the external surface via a punctum
Contain laminated keratin
Lumen is lined by yhin flattened sqamous epithelium which has a granular layer
84
What is the macroscopic appearance of an epidemoid cyst?
White/pale nodule with pultacious contents
85
How does trauma alter the macroscopic appearance of an epidemoid cyst?
Keratin entering the surrounding dermis leads to a granularmatous foreign body giant cell reaction
Seen as swelling, tenderness, redness
86
What is the microscopic appearance of an epidemoid cyst
Laminated keratin
Lumen lined by thin flattened squamous epithelium with a granular layer
87
What is a pilar (tricholemma) cyst
Similar to epidemoid cysts
Interdamal lesion +/- open to external surface fire a punctum
Almost entirely in the scalp
88
What is the macroscopic description of a pilar cyst?
Firm nodule
White outer surface
White to brown firm cut surface
89
What is the microscopic appearance of a pilar cyst?
Contain compact and cohesive keratin
Lined by squamous epithelium which resembles hair follicles
Lacks a granular layer
90
What is a dermatofibroma?
A reactive lesion rather than a true benign lesion
Common
91
Where are dermatofibromas found?
Limbs of young and middle aged people
92
What is the macroscopic appearance of a dermatafibroma?
Single firm raised nodule
Ranging from white to brown
Peripheral ring of hyperpigmentation
93
What is the microscopic appearance of dermatafibroma?
Lies in the dermis
Ill defined margins
Composed of a regularly arranged spindle cells resembling fibroblasts with intervening collagen fibers
Ratio of cells to collagen vary
Overlying epidermis shows prominent basal layer pigmentation
If marked change can mimic invasive carcinoma
94
What is a dermatofibrosarcoma protuberance?
A low grade sarcoma
95
Where do dermatofibrosarcoma protuberance appear?
Skin most commonly on the trunk
In young adults
96
What is the microscopic appearance of dermatafibrosarcoma protuberance?
Spindle cells with mild pleomorphism
Occasional mitotic figures
Originates in dermis but infiltrates laterally to adjacent dermis and deeply to subcutaneous adipose tissue
97
What are the implications of having a dermatofibrosarcoma protuburns?
Often infiltrates more than apparent leading to incomplete excision and invariably reoccurrence with more local spread metastases
Is rare but is usually bloodborne when it occurs
Some lesions develop areas of higher grade malignancy. This can be seen in a rapid increasing size
98
What are skin polyps?
Also referred to as skin tags
Benign growths in skin
Often occur in folds such as axilla, genital area, neck
Can be fiberoepithelial or lipomatous
Rarely treated unless catching or bleeding
99
What is the macroscopic appearance of a skin polyp?
Skin covered module
No pigmentation
Can be red
Maybe pedunculated
100
What is the microscopic appearance of skin polyps?
Spindle cells
Often slightly cellular to subcelluer with extensive oedema
Adipose tissue if lipomatous
101
What our skin warts?
Lumps on skin caused by viruses Spread through contact
Usually resolve spontaneously Tropical treatments can be used
Occur in non-traumatized skin
102
What is the microscopic appearance of a skin wart?
Irregular thickened epidermis covered in a thick layer of hyperkeratosis
Prominent granular layer
Areas of pale vaculated cells in the upper stratum spinosum
Chronic inflammatory infiltrate in dermis
103
What is impetigo granuloma annulare?
Common inflammatory skin condition
104
Where does impact impetigo granuloma annulare occur?
In children usually in the extremities but can occur anywhere
105
What is the macroscopic appearance of impetigo granuloma annulare?
Erythromatus papule or plaque usually in a circular pattern
106
What is the microscopic appearance of impetigo granuloma annulare?
There are two patterns
Palisaded granulomas with central collagen, degeneration, peripheral histiosites and lymphocytes
Histiosites among collagen bundles and interstitial mucin
107
What are Lipomas?
Benign tumour of soft tissue can occur in many sites but subcutaneously is the most common upper back, extremities and abdomen
108
What is the macroscopic appearance of a lipoma?
Painless subcutaneous mass w
Well circumscribed
Nodular
Cut surface is homogeneous
Fatty appearance
Usually <5cm
109
What is the microscopic appearance of Lipomas?
Proliferation of mature adipocytes
Fiberous septa can be present
Fat necrosis may be seen if large or undergone trauma
110
What is a neurofibroma?
Benign peripheral nerve sheath tumor
Can show atypia and can have malignant transformation
111
Who can be affected by neurofibroma?
20 to 30s
Both sexes
112
How do neurofibromas appear clinically?
Painless
Slow growing
Solitary
Skin coloured
Flaccid
Rubbery to firm papule or nodule
113
What is the microscopic appearance of a neurofibroma?
Proliferation of all elements of the peripheral nerves
Swan cells
Mast cells
Wagner Messiner carpuscles
Pacinian corpsules
Axons
Fibroblasts
Collagen
114
What is seborrhoeic keratosis?
A non cancerous skin growth
Wart-like bump or plaque
115
Where is seborrhoeic keratosis found?
Usually face, neck, chest or back but can occur anywhere exposed to sun
116
What is the clinical presentation of seborrhoeic keratosis?
Slow growing
Do not spread
Can be singular or multiple
Average age > 50y
Incidents increases with age
Stuck on appearance
Usually dark in color
117
What is the macroscopic appearance is seborrhoeic keratosis?
Dark coloured
Warty
Plaque/papule
Well-defined
Waxy or greasy surface
Stuck on appearance
118
What is the microscopic appearance of seborrhoeic keritosis?
Intra epidermal
Well demarcated edges
Baseloid keratinocyte proliferation
Without dysplasia
Prominent melanin pigment at basal layer
Nuclei are bland and uniform
No significant mitotic activity
Pseudocysts
Thickened and elongated rete ridges
119
What is the differential diagnosis of seborrhoeic keratosis?
Melanocytic naebi
Solar lentigo
Pigmented basal cell carcinoma
Malignant melanoma
120
How are seborrhoeic keratosis usually treated?
Left alone
121
What is actinic (solar) keratosis?
Inter epidermal keratinocyte lesion that
Most common precursor for cutaneous squamous cell carcinoma
122
Where does actinic keratosis occur?
Sun expose sites
Most commonly face, scalp, upper chest and distal arm
123
Who does actinic keratosis usually occur in?
Increasing age > 40y
Pale skin
Prolonged immunosuppression
Males > females
124
What are the risk factors for actinic (solar) keratosis?
Chronic sun damage
Chronic immunosuppression
125
What is the clinical presentation of actinic keratosis?
Single or multiple
Erythematosus
Hyperkeratotic
Macules or papules
Usually <1 cm
Pigmentation
Ulceration
126
What is the macroscopic appearance of actinic keratosis?
Rough
Scaly patch
Slightly raised
White-red
Waxy
127
What is the microscopic appearance of actinic keratosis?
Atypia of basal keratinocytes
Loss of polarization
Overcrowding
Overlapping
Mild inflammatory infiltrate
Can progress 50 to 60% atypia
128
What are the implications of actinic keratosis?
Can progress to squamous cell carcinoma
129
How is actinic keratosis treated?
Excision or cryothermy
130
What additional tests can be carried out on acinic keratosis and what are the expected results?
P53 positive
Cyclin D1 positive
SOX10 negative
HMB45 negative
131
What are the differential diagnosis for actinic (solar) keratosis?
Squamous cell carcinoma
Bowen's disease
Linenoid keratosis
132
What is Bowen's disease?
Very early form of squamous cell carcinoma also called squamous cell carcinoma in situ
133
Where does Bowen's disease usually occur?
Usually on skin NOT exposed to UV so trunk
134
Who is at risk of Bowen's disease
Usually asymptomatic but can ooze pus, bleed and become crusted
More common in females
Fair skin,
Blue Eyes
Bonde hair
135
What are the risk factors of Bowen's disease?
UV radiation
Immunosuppression
Carcinogens
136
What is the clinical presentation of Bowen's disease?
Can be singular or multiple
Slow growing
Persistant reddish brown patch or plaque
Dry scaly skin
137
What is the macroscopic appearance of bowen's disease?
Slightly raised
Large scaly
Erythromatus plaque with an irregular border
138
What is the microscopic appearance of Bowens disease
Full thickness keratinocytes
Atypia
Altered maturation
Multi-nucleation
Mitotic figures
139
What are the implications for Bowen's disease?
Can progress to squamous cell carcinoma
140
How is Bowen's disease treated?
Excision
141
What additional tests can help diagnose bowen's disease?
P16 and 34BE12 positive
142
What is the differential diagnosis of bowen's disease?
Actinic (solar) keratosis
Squamous cell carcinoma
143
What is lichenoid keratosis?
Benign skin condition also known as lichen planus
144
Where does lichenoid keratosis occur?
Sun exposed areas chest and upper extremities
145
Who does lichenoid keratosis present in
Fair skin
30-80y
Females > males
146
What are the risk factors for lichenoid keratosis?
UV exposure
147
What is the clinical presentation of lichenoid keratosis?
Small inflamed macule or thin pigmented plaque usually solitary with a lichenoid reaction
148
What is the macroscopic appearance of lichenoid keratosis?
Small
Raised
Scaly lesion
Usually <1cm
Can vary from pink-red but can change to purple, grey or deep brown
149
What is the macroscopic appearance of lichenoid keratosis?
Thickening of epidermis
Hyperkeratosis
Hypergranulosis
Band of the inflammatory infiltrate causing basal cell damage and separation of epidermis from dermis
150
How is lichenoid keratosis treated?
Can clear on its own
Topical medication
C+C removal
Excision
151
What is the differential diagnosis lichenoid keratosis?
Basal cell carcinoma
Solar lentigo
Seborrhoeic keratosis
Actinic keratosis
152
What is the differential diagnosis lichenoid keratosis?
Basal cell carcinoma
Solar lentigo
Seborrhoeic keratosis
Actinic keratosis
153
What is bullous pemphigoid?
Autoimmune disease starts as an itchy raised rash and can progress to large blisters
154
Where can bullous pemphigoid be found?
Inner and anterior thighs groin flexor surfaces of the upper extremities and lower abdomen
155
Who is affected by bullous pemphigoid?
Usually in the over 60s
Incidence increases with age
156
What is the clinical presentation of bullous pemphigoid?
Mild to severe itch
Papular rash
Initially forming tense bulla containing serous fluid or hemorrhage
Unusual to have mucosal involvement
157
What is the macroscopic appearance bullous pemphigoid?
Red
Scaly
Raised rash
And/or tense bulla, can also rupture
158
What is the microscopic appearance of bullous pemphigoid?
Subepidemal blister
Mixed inflammatory infiltrate with eosinophils in the dermis and blister cavity
159
How is bullous pemphigoid treated?
Corticosteroids or drugs
160
How does bullous pemphigoid appear on immunofluorescence?
C3>IgG
C3 deposition along basement membrane, hair follicles, eccrine glands
161
How does bullous pemphigoid appear on salt split skin analysis?
Localisation of immuno reactant to either roof only or roof and blister
162
What are the differential diagnosis is diagnoses for bullous pemphigoid?
Bullous lupus erythematosus
Dermatitis herpetiformis
Linear IgA bullous disease
163
What is bullous pemphigus?
Autoimmune skin disease against various epidermal cell Junction proteins
164
Where is bullous pemphigus usually found?
Skin
Mucosae
Nails
165
Who does bullous pemphigus usually affect?
40-60y
166
What is the clinical presentation of bullous pemphigus?
Flaccid bullae or crusted erosions involving skin or mucosa
Painful
Erosion by slight friction
167
What is the macroscopic description of bullous pemphigus?
Flaccid bullae
Pink-red, dark reddish brown skin
168
What is the microscopic appearance of bullous pemphigus?
Suprabasal acantholysis
Basal layer attached (tombstoning)
Intraepidermal eosinophils
Follicular involvement
169
How does bullous pemphigus appear with immunofluorescence?
Intracellular IgG and C3 in the epidermis (chicken wire pattern)
170
What is the differential diagnoses for bullous pemphigus?
Grover's disease
Hayley Haley disease
Bullous impetigo
171
What is dermatitis hepatiformis?
Acquired autoimmune subepidermal blistering disease due to gluten exposure
172
Where is dermatitis hepitiformis usually found?
Elbows
Knees
Buttocks
Back
Posterior shoulder
Neck
Rarely involves oral mucosa
173
Who is likely to suffer from dermatitis herpetiformis?
20/40y
M>F
Common in northern Europeans
174
What is the clinical presentation of dermatitis herpetiformis?
Pimhead sized grouped vesicles on an erythromatus base
May appear as erosions
175
What is the macroscopic appearance of dermatitis herpetiformis?
Small (3-5mm) clustered papules and vesicles that are symmetrical
176
What is the microscopic appearance of dermatitis hepatiformis?
Early on superficial perivascular lymphocytic and neutrophilic infiltrate subepidermal vesicles/blisters
177
How does dermatitis herpetiformis appear under immunofluorescence?
Commonly Iga deposits in the dermal papillae
C3 may also deposit in the dermal papillae
178
What are the differential diagnoses for dermatitis hepatiformis?
Linear IgA dermatosis
Bullous pemphigoid
179
What is lupus erythematous?
A multi system autoimmune disease that affects skin and internal organs
Cutaneous lupus erythematous can be acute or chronic in nature
180
Where can lupus erythematous be found?
Discoid form = face, skull, conchal bowl
Other forms = lateral face, upper trunk, upper extremities
181
Who is affected by lupus erythematous?
Most common in women 20-30y
Persons of African descent > Caucasians
182
What is the clinical presentation of lupus erythematous?
Erythematous and scaly plaques with hyperpigmentation
Scalp involvement may lead to scarring, dispigmentation and alopecia
183
What are the risk factors for lupus erythematous
Sun exposure
Smoking
184
What is the macroscopic appearance of lupus erythematous?
Red scaly plaques
185
What is the microscopic appearance of lupus erythematous?
Epidermal atrophy
Flattening of rete ridges
Hyperkeratosis +/- basement membrane thickening
186
How does lupus erythematous appear on immunofluorescence?
IGM (granular) is continuous in the sun exposed skin and disrupted in protected skin
187
What is the differential diagnosis of lupus erythematous?
Lichen planus
188
What is basal cell carcinoma?
Most common form of skin cancer arises from interfollicular epithelium it has a low death rate and rarely metastases
189
Where is BCC most commonly found?
Sun exposed skin
Head and trunk
Rarely on mucosal surfaces
Palms and soles
190
Who does BCC effect?
Fair skinned
Middle-aged +
Tumours in younger people are more aggressive
191
What is the clinical presentation of BCC?
Nodular variant = pearly pink or flesh coloured papule/nodule +/- ulceration, rolled borders
Superficial variant = scaly macules/patches/plaques with erythematous surface
Pigmented variant = resembles nodular or superficial variants but has additional pigment
192
What are the risk factors for BCC?
Sun damage
Fair skin
Family history
Increasing age
Immunosuppression
Previous skin cancer
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How is BCC treated?
Excision
Moh's micrographic surgery
Curatage
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What is the macroscopic description of BCC?
Pale/pigmented
Flat/raised
Rolled edges
Well defined
Appearance depends on variant
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What is the microscopic appearance of BCC?
Nests of basaloid cells with peripheral referral palisading
Associated with fibromxyoid stroma
Extracellular matrix composed of immature collagen and fibroblasts separating and surrounding the tumor cells
Pleomorphism
Variable mitotic activity
Pigmented will also have melanocytes within the tumour
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What additional tests can be carried out on BCC and what are the expected results?
AE1/3, BEREP4, p63. positive
CK20, SOX10, Melan A. negative
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What are the differential diagnoses for BCC?
Squamous cell carcinoma
Merkel cell carcinoma
Clear cell carcinoma
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What are the implications of BCC if left untreated?
Grow deeper into skin
Rarely metastases
Extremely destructive to adjacent tissues
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What is SCC?
Squamous cell carcinoma
Malignancy of epidermal keratinocytes that display variable degrees of differentiation and cytological features
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Where is SCC most commonly found?
Most often sun exposed areas scalp, ear, lip, nose, eyelid are all high-risk areas
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Who is most likely to be affected by SCC?
M>F
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What is the clinical presentation of SCC?
Erythematous scaly thin papule/plaque
Thicker tumours are typically erythematous plaque/nodule with ulceration
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What are the risk factors of SCC?
UV radiation
Chronic immunosuppression
Actinic keratosis
Burn/scars
Chronic ulcers
Chronic inflammation
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How is SCC treated?
Excision
Moh's micrographic surgery
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What is the microscopic appearance of SCC?
Hyperkeratotic scaly plaque
May have injuration, ulceration, hemorrhage
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What is the microscopic appearance of SCC?
Associated precanceeous lesions can be well, moderately, poor, or undifferentiated
Well differentiated = abundant keratinerisation, minimal pleomorphism, mitosis basaly located,
Moderately differentiated = focal keratinisation, features are well and poorly defined
Poorly differentiated = no/minimal keratinisation, marked nuclear atypia, may not be recognizable as squamous cells
Undifferentiated = IHC required for diagnosis
All types have downwards invasion of the dermis and subcutaneous tissues
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How does IHC appear for SCC?
AE1/3 MNF positive
CK20 SOX10 negative
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What is the differential diagnosis for SCC?
Lupus erythematous
Lichen planus
Proliferative actinic keratosis
Basal cell carcinoma
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What are the implications if SCC is left untreated?
Can spread to nearby lymph nodes, bones, organs
Metastases are rare but not as rare as in BCC
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What is a cutaneous neuroendocrine carcinoma?
Also named Merkel cell carcinoma
It is a rare and aggressive type of cancer that forms on or just below the skin
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Where are Merkel cell carcinamers most often found?
Sun expose skin
Head and neck > extremities > trunk
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Who is mostly to be affected by Merkel cell carcinoma?
Elderly caucasians (70y +)
M>F
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What is the clinical presentation of Merkel cell carcinoma?
Painless
Rapidly growing
Flesh coloured - red/violet nodule
AEIOU = Asymptomatic Expanding rapidly Immunosuppression Older than 50 UV exposed site
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How is Merkel cell carcinoma treated?
Wide local Excision
Sentinel lymph node biopsy
+/- radiotherapy
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What is the macroscopic description of Merkel cell carcinoma?
Violaceous, lobulated, polyploid cutaneous nodule
Fleshy - tan/brown lesion
Nodular or ill-defined silhouette
Variable ulceration
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What is the microscopic Merkel cell carcinoma?
Nodular or diffusely infiltrative tumour within the dermis and often subcutaneous tissue
Variable mixture of nodules/sheets/nests/trabeculae of neoplastic cells
Small round blue cells
High N/C ratio
Round/oval nuclei
Salt and pepper chromatin
Indistinct nucleoli
Scanty cytoplasm
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What additional tests can be performed on Merkel cell carcinoma and what are the expected results?
CAM5.2, AE1/3. positive
CK7, S100. negative
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What are the differential diagnoses for Merkel cell carcinoma?
BCC
Lymphoma
Small cell carcinoma
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What are the implications for untreated Merkel cell carcinoma?
Grow rapidly
Metastasize even to internal organs
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What are benign melanocytic lesions?
Naevi
Very common
Acquired of congenital
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What are the three main types of naevi?
Junctional
Compound
Interdamal
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What is a junctional naevi?
Melanocytic y proliferation restricted to basal layer of epidermis
223
Where do junction naevi occur?
Usually on non- sun exposed skin Palms/soles
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Who can junctional naevi affect?
Occur at any age
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What is the macroscopic description of a junctional naevi?
Small
Flat or slightly elevated
Non-hairy
Deeply pigmented
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What is the microscopic appearance of junction naevi?
Rounded nests of melanocytes on epidermal side of dermalepidermal junction
Originating from the tips of the rete ridges
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What are the differential diagnoses of junctional naevi?
Lentigo
Melanoma
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What is a compound naevi?
Features both junctional and intradermal components
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Who does a Compound naevi affect?
High incidence in second decade
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What is the macroscopic appearance of a compound naevi?
Elevated or dome-shaped
Less pigmented than junctional naevi
Rarely undergo malignant transformation
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What is the microscopic appearance of a compound naevi?
Junction of component = nests regularly distributed at the base of the rete ridges
Dermal component = nests or linear pattern separated by collagenous stroma
Often clusters of inflammatory cells at the base of the naevi
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What is an intradermal naevi?
All the melanocytes are in the dermis
Most common form of adult naevi
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What is the macroscopic description of a intradermal naevi?
Flesh coloured/lightly pigmented
Malignant potential is rare
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What is the microscopic appearance of an intradermal nearby?
Small nests of melanocytes in upper dermis
Variable pigmentation and cellularity
Multinucleated melanocytes
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What is the microscopic appearance of an intradermal nearby?
Small nests of melanocytes in upper dermis
Variable pigmentation and cellularity
Multinucleated melanocytes
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What is a lentiginous naevi?
Often a benign role with with an increase in size, formation of irregular borders, or peripheral changing color
Multiple pigmented macules or papules within a pigmented patch
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What is the microscopic appearance of lentigenous naevi?
Elongation of rete ridges
Small nests at the tips
No atypia
Pagetoid spread or dermal fibrosis
Area of lentigenous junctional melanocytic proliferation beyond the lateral border of the underlying dermal naevus
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What are atypical/dysplastic melanocytic lesions?
Pigmented lesions that share clinical and histological features with common naevi and melanoma
239
Where can atypical/dysplastic melanocytic lesions be found?
Anywhere, more common on trunk or sun exposed skin
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Who do atypical/dysplastic melanocytic lesions commonly affect?
Common
Apparent following puberty
History of sunburn (acute)
Can be inherited
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What are the clinical presentation of atypical/dysplastic melanocytic lesion?
Categorised histologically
Usually > 5mm
Irregular borders
Pigmented erythematous rim
Varied pigmentation pink-dark brown
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What is the microscopic appearance of atypical/dysplastic melanocytic lesion?
Singular or amalgamated
Diffused pattern
Irregular border
Irregular pigmentation
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What is the microscopic appearance of atypical/dysplastic melanocytic lesion?
Cytological atypia
Epidermal component extends at least three rete ridges beyond the lateral margin of the dermal component
Bridging of adjacent nests along with the rete ridges
Regular nests - shapes and sizes Increase nuclear size
Hyperchromatic nuclei
Irregular nuclear membrane
Prominent nucleoli
Pleomorphism
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What are the implications of leaving atypical/dysplastic melanocytic lesions untreated?
Most won't progress to melanoma but the potential is there
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What is lentigo malign?
A subtype of melanoma
Usually refers to the in situ form
The invasive form is called lentigo maligna melanoma
246
Where is lentigo maligna commonly found?
Face
Neck
Ears
Scalp
Forearms
Dorsal hands
247
Who is usually affected by lentigo maligna?
Usually over 50y
Develops at sites of chronic, continuous, cumulative sun exposure
248
What are the clinical features of lentigo maligna?
Growing
Irregularly pigmented lesion
Raised papular or nodular lesion indicates vertical growth phase
249
What is the macroscopic appearance of lentigo maligna?
Flat/growing
Irregularly pigmented lesion
Can develop a raised papular/nodular focus indicating tumogenic growth
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What is the microscopic appearance of lentigo maligna?
Single and nested melanocytes
Crowded pagetoid scatter
Associated irregular epidemal hyperplasia
Melanocytes can be small cells, dark nuclei, scanty cytoplasm
Epitheloid pigmented melanocytes
Spindled melanocytes
251
What additional tests can be used for lentigo maligna and what are the expected results?
Melan A, SOX10 positive
p63 negative
252
What are the differential diagnoses for lentigo maligna?
Lentigo
Dysplastic naevis
SCC
253
What is malignant melanoma?
Malignant melanocytic tumor arising from melanocytes
254
Where does malignant melanoma commonly occur?
Cutaneous anywhere but common on lower extremities in women and trunk in males
Extra cutaneous can occur in the anal rectal region upper aerodigestive tract and sinonasal tract
255
Who does malignant melanoma commonly affect?
1% of all skin cancer
Increasing incidents
Slightly more males than females
256
What are the risk factors for malignant melanoma?
Fair skin
Family history
Intense intermittent sun exposure
Increased mole count
Immunosuppression
257
What are the clinical features of malignant melanoma?
Flat/slightly elevated nodular, polyploid or verrucous pigmentated lesion
Can be colorless
ABCDE
258
What is the macroscopic appearance of malignant melanoma?
ABCDE
Extend of appearance depends on variant
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What is the microscopic appearance of malignant melanoma?
**Superficial spreading melanoma** asymmetrical proliferation of atypical melanocytes
Predominantly single melanocytes
Prominent pagetoid spread
**Lentago malignant melanoma**
Solitary melanocytes
A few nests along the epidermal dermal junction
Nests of various shapes and sizes
Extend into hair follicles
**Acral lentigenous melanoma**
Acral location
Asymmetrical lentigenous proliferation
Eccrine duct involvement
**Nodular melanoma**
No radial growth phase
No ABCDE
Junctional component not beyond the dermal component
Nodular dermal proliferation of atypical melanocytes
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What additional tests can we carried out formalignment melanoma and what are the expected results?
S100, SOX 10, Melan A, HMB45, Ki67 positive
p16, CD34, CD45. Negative
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What are the differential diagnoses for malignant melanoma?
Dysplastic Naevi
Spitz tumor
Bowen's disease
Merkel cell carcinoma
