Skin Diseases Flashcards
1
Q
Define Hyperplasia
A
Increase in the number of cells
2
Q
Describe Hyperkeratosis
A
Thickening of the stratum corneum
3
Q
Define Acanthosis
A
thickened squamous cell layer
4
Q
Describe Eczema
A
- affects 20% of adults & 10% children
- unpredictable course, pattern of recurrence
- associated with auto immune conditions
5
Q
What are the different forms of eczema?
A
- Atopic = most common form
- Irritant = caused by irritant substance
- Allergic = caused by sensitivity to a substance that others find benign
- Rare types = Seborrheic & Varicose
6
Q
Describe Eczema related to Filaggrin mutations
A
- filaggrin is important in keeping a healthy protective barrier on the epidermis
- too little filaggrin to build & maintain the barrier, fluid can escape & allows pathogen/allergens to enter body
7
Q
Describe Atopic Eczema
A
- most common form, usually diagnosed before 1 yr old
- pink/red on skin
- can be cyclical with flare ups & better periods between symptoms
- harder to spot on darker skin tones looks purple/grey/brown
8
Q
Describe Allergic contact dermatitis
A
contact with substances causes sensitised skin
9
Q
Describe Irritant contact dermatitis
A
- type of eczema that occurs when the body contacts a particular substance which is a known irritant
10
Q
Describe Infantile Seborrheic eczema
A
- infants can develop it between 2 weeks & 12 months old
- cradle cap
- slightly red scaly or crusty yellow patches on scalp
- can also be on face or diaper area then spread
11
Q
Describe Varicose Eczema
A
- effects lower legs & is related to vascular problems
- blood flow - due to circulatory deficiency blood pools & stagnates in capillaries
12
Q
Describe Eczema Histology
A
- defining feature = Epidermal Spongiosis
- epidermal spongiosis = intracellular oedema which resides in between keratinocytes
- more inflammatory cells
- increased Langerhans cells
- broken areas of the stratum corneum
13
Q
Define Orthokeratosis
A
hyperkeratosis without parakeratosis
14
Q
Define Parakeratosis
A
flattened keratinocyte nuclei within the stratum corneum
15
Q
Describe the appearance of psoriasis
A
- plaques/sores = caused by abnormally fast skin regeneration, skin thickens & plaques fall off
- inflamed joints
- sore eyes
- nail disruption
16
Q
What are some treatments for psoriasis ?
A
- emollients
- salicylic acid = removes excess skin
- steroids = mild/short term use only
- sunlight/ vitamin D
17
Q
Describe Basal cell carcinoma
A
- 80% of skin cancers are BCC
- effects basal epithelial cells at the base of the epidermis
- treatment often involves surgical removal
18
Q
Describe the histology of basal cell carcinoma
A
- connective tissue stroma grows in between pockets of tumour
- tumours are heavily nucleated, with low amount of cytoplasm around tumour cells
- BCC often have clefts or joints
- necrotic bodies can also form
19
Q
Describe Squamous Cell Carcinoma
A
- 2nd most frequent type
- involves squamous cell layer - most likely on sun-exposed skin
- more invasive than BCC & not likely to metastasize
- manifests as a persistent patch which is scaly, has irregular borders & becomes crusty & may bleed
20
Q
Describe squamous cell carcinoma histology
A
- nests of squamous epithelial cells arising from the epidermis & extending into the dermis
- malignant cells are often large & abundant eosinophilic cytoplasm & large often vesicular nucleus
21
Q
Describe Melanoma
A
- effects pigment cells melanocytes found in the epidermis
- more aggressive than BCC & SCC
- can effect body parts not exposed to sun
- can metastasize to brain, liver and lungs
- grades of melanoma graded on Clark level scale
22
Q
Describe Merkel cell carcinoma
A
- relatively rare but aggressive
- more common in sun exposed areas of skin
- can metastasise to brain, bones, liver & lungs
- 2nd most common cause of skin cancer deaths
- risk factors = over 50, male, white, HIV +, weakened immune systems
23
Q
Describe the hisology of Merkel cell carcinoma
A
- tumour centred in dermis
- tumour takes form on either sheet, nest or ribbon formations
- outlines of cells often merge or look like lymphocytes
24
Q
Describe Kaposi’s sarcoma
A
- cancer is formed in the cells that line blood vessels & lymph vessels
- 2 types
- type 1 common in men over 50 from caucasian & middle Eastern backgrounds. slow to grow & usually treatable
- type 2 = aggressive & associated with people with weakened immune systems - presents with red/purple or brown lesions
25
Describe the histology of Kaposi's sarcoma
- epidermal changes observed can be hyperkeratosis & acanthosis & ulceration
- dermal proliferation is comprised of spindle cell proliferation of endothelial cells
- forms around or near blood vessels
26
Describe Dermatofibrosarcoma protuberans
- cancer arises from cells found in the dermis
- presents like a cyst, scar or bruise
- most likely to form on arms, legs or torso
- treatment includes Mohs surgery, next level is radiation therapy
27
What is Mohs surgery?
- tissue is removed in layers and assessed histologically until no cancerous tissue is found
28
Describe the histology of Dermatofibrosarcoma protuberans
- DFSP has characteristic morphology with islands of uniform spindle cells
- immunohistochemically, shows diffuse expression of CD34
- thinning of epidermis
29
Describe Sebaceous carcinoma
- starts in sebaceous glands in dermis
- usually a painless lump or thickening of skin near eye
- 75% are periocular & 25% are extraocular
- therapies includes Mohs surgery, radiation therapy for later stages
30
Describe the histology of sebaceous carcinoma
- dermal based tumour with focal connection to the epidermis or follicular epithelium
- can be rounded nodular aggregates or angulated infiltrative aggregates
- can appear cystic with central necrosis
