Benign skin lesions (dermatofibroma, seborrhoeic keratoses, naevi) Flashcards
What are the three types of naevi?
Which one is flat?
Which size moles are at greater risk of malignant change?
larger ones
Is it reasonable to excise benign moles prone to mechanical irritation?
Yes
What is this?
Seborrhoeic wart/keratosis aka basal cell papillomas
Describe the development of seborrhoeic warts.
Light brown raised lesions –> gradually grow and darken –> surface gets rougher.
They can vary in shape and size, from one centimeter to several in diameter.
What is this?
Dermatofibroma
When can seborrhoeic warts resemble squamous cell carcinomas?
When they get inflamed and crusty
What is the management of seborrhoeic keratosis?
Curettage
OR liquid nitrogen therapy
Should be done if there is diagnostic uncertainty or probelms e.g. itchy
They are relatively easy to remove.
Define dermatofibroma.
AKA cutaneous fibrous histocytoma
Common benign fibrous nodule usually found on the skin of the lower legs,
What causes dermatofibroma?
- May be a reactive process or a true neoplasm e.g. after insect bites, injections, rose thorn injuries
- More common in those with altered immunity e.g. HIV, immunosuppression, autoimmune conditions
What are the clinical features of dermatofibroma?
- Solitary firm papule or nodule
- Usually on lower legs
- 0.5-1.5cm in diameter
- Tethered to the skin surface and mobile over subcutaneous tissue
- “Dimple sign”
- Colour ma be pink to light brown in light skin, dark brown to black in dark skin
NB: usually asymptomatic
What are the complications of dermatofibroma?
May be traumatised by razor
Multiple eruptions may occur especially in immunosuppression
How is a dermatofibroma diagnosed?
Clincial diagnosis
Dermoscopy - central white area surrounded by a faint pigment network
What is the management of dermatofibroma?
Usually reassurance is enough and other treatments often cause recurrence and are rarely successful e.g. cryotherapy, shave biopsy, laser.
Define seborrhoeic keratoses.
A harmless warty spot that appears during adult life as a common sign of skin ageing. Some people have hundreds of them.
AKA basal cell papilloma, senile/brown/wisdom wart, barnacle.
What are the features shown here?
- Flat or raised papule or plaque
- 1 mm to several cm in diameter
- Skin coloured, yellow, grey, light brown, dark brown, black or mixed colours
- Smooth, waxy or warty surface
- Solitary or grouped in certain areas, such as within the scalp, under the breasts, over the spine or in the groin
Stuck on the surface like barnacles. Do not occur on palms or soles.
