Benign Skin Lesions Flashcards
What is Seborrhoeic keratosis?
Benign epidermal tumours
Aka basal cell papillomas
What causes Seborrhoeic keratosis
Benign proliferation of epidermal keratinocytes
Very common in ageing skin
How does Seborrhoeic keratosis present, when is a red flag raised and how is it managed
Well demarcated, greasy, raised brown lesions on face and trunk
Leser-Trelat sign- eruptive appearance of many lesions may be malignant
Doesn’t need removal unless patient wants it
What is a Dermatofibroma
Bites/minor trauma -> fibroblast proliferation
Common immunosuppression patients
How does Dermatofibroma present, and how is it investigated and managed?
Firm unchanged lesion, skin coloured or brown
Sometimes itchy, dimples when squeezed
Dermoscopy/biopsy if needed
Management- nothing
How do benign pigmented lesions differ from malignant ones
They tend to be even, have a well defined margin, be symmetrical, and not change over time
What are ephleis?
Freckles- patchy melanin pigmentation after UV exposure
What is the gene associated with freckles?
MC1R- one defective copy
2 defective copies -> freckles and red hair
What are actinic lentigenes?
‘Age spots’
Found on face, forearms and hands, related to long term UV exposure
Histology of actinic lentigenes
Elongated rete ridges in epidermis
Inc. melanin and basal melanocytes
What are melanocytic naevi
Common moles
What are the types of moles?
Congenital- combined, compound, junctional, intradermal
Acquired- blue, dark
Features of intradermal naevi
Entirely dermal
Dome shaped, verrucous
Usually flesh coloured
Hairy
Some telangiectasia
Dysplastic naevi
Angrier looking
May look similar to melanoma, but unlike melanoma epidermis not affected
