Naevus
- A nevus is a benign lesion of melanocytes in the skin or oral mucosa
- Can be pigmented or non-pigmented (most are pigmented)
- Histological classification
- Junctional nevi
- Flat, well-demarcated brown macules
- Grows in the epidermis at the dermal-epidermal junction
- Compound nevi
- Elevated
- Grows in the epidermis at the dermal-epidermal junction and in the dermis
- Dermal nevi
- Elevated
- May be hard and grow hair
- Grows in the dermis only
- Junctional nevi
- Clinical classification
- Congenital
- Small (< 1,5 cm)
- Medium
- Giant (> 20 cm)
- Acquired
- Common acquired nevus
- < 6 mm
- Symmetric
- Homogenous surface
- Even pigmentation
- Round or oval shape
- Sharply demarcated border
- Atypical/dysplastic nevus
- Share some similarities to melanoma
- Must be differentiated from melanoma
- Fried egg or target-shaped
- May evolve
- Atypical colour
- Irregular, poorly demarcated
- Spitz nevus
- Not brown, rather pink, tan, red, etc.
- In children
- Halo nevus
- Nevus surrounded by halo of depigmentation
- Reed nevus
- Very dark
- On limbs
- Nevus spilus
- Tan macule speckled with smaller, darker macules
- Blue nevus
- Common acquired nevus
- Congenital
- Dysplastic nevus syndrome
- Also called familial atypical multiple mole and melanoma syndrome (FAMMM)
- High number (> 50) of common and atypical nevi and family history of melanoma
- Almost 100% of developing melanoma
- Diagnosis
- History
- Family history?
- History of skin lesions?
- History of sunburns?
- When did nevus appear?
- Has it changed?
- Physical examination
- Assess skin type
- Examination with dermoscope
- ABCDE
- Ugly duckling sign
- History