Benign Skin Lesions

Question 1

Seborrheic keratosis

Answer 1

Well circumscribed, stuck on
Waxy texture
Verrucous, granular, or crumbly surface
Variable size, shape, colour
Can have keratin plugs or horn pearls
Can get inflamed and become itchy or painful
No sebaceous gland involved - its epidermal hyperproliferation (hyperkeratosis)

Question 2

What is the difference between

1. Parakeratosis
2. Orthokeratosis

Answer 2

1. Retention of nuclei in the stratum corneum

2. Hyperkeratosis without nuclei (normal)

Question 3

Epidermoid cyst

Answer 3

Cystic, firm - pore that is plugged by keratin
Yellow (but can be blue/grey if the keratin is oxidized)
Look for the pore!
May become inflamed and infected

Question 4

3 types of melanocytic nevi (what are they formed by)

Answer 4

1. Junctional (melanocytes localized to junction between epidermis and dermis - medium to dark brown, macular)
2. Compound (melanocytes at junction and in dermis - brown to skin coloured, papular)
3. Intradermal (melanocytes localized to dermis - skin coloured to light brown, papular)

Question 5

Hypertrichosis

Answer 5

Hair in mole

Has no positive or negative correlations with it

Question 6

Blue nevus

Answer 6

Dark blue-grey macule or papule
Well circumscribed
Melanin localized to dermis
Common on nose and scalp

Question 7

Acrochordon

Answer 7

Skin tag - epidermis and dermis
Skin coloured to brown pedunculated papules
Usually multiple
1-5 mm
Flextures (neck, axillae, groin, eyelids)
No associated with internal disease

Question 8

Dermatofibroma

Answer 8

Fibroblast or histiocyte derived
Skin coloured to brown nodule
Firm, indurated texture
Extremities
Female > male
Dimple sign (puckers when squeezed)

Question 9

Infantile hemangioma

Answer 9

Benign overgrowth of endothelial cells
Common
Congenital
Red plaques or nodules
Self regressing over months to years (50% gone by 5, 90% gone by 9)

Question 10

Cherry angioma

Answer 10

Bright red papule
1-4 mm
Usually multiple
Adults

Question 11

Lipoma

Answer 11

Subcutaneous nodule
Skin coloured
Firm, rubbery texture
Mobile
Sometimes painful

Question 12

Neurofibroma

Answer 12

Tumor of the supporting cells around the neuron
Soft fleshy papule or plaque
Often pedunculated
Usually asymptomatic
Solitary or multiple