Module 6: Facial lesions Flashcards
Ddx pigmented macule on the face
Pigmented AK
LPLK
LM
What does term “pseudo-network” refer to?
Structureless brown pigment interrupted by follicular openings.
Is the term “pseudo-network helpful?
No. Pattern is non specific.
Why do we not see pigmented network on the face?
Rete ridges are flat
Types of circles
- Thin lines around follicular opening.
2. Dots arranged in circles around follicular openings,
What type of pattern is dots arranged evenly throughout lesion.
Pattern of dots
Pattern of curved lines is clue to …
Solar lentigo, no matter where located
Classical Dermoscopy criteria for melanoma in situ on face
grey dots arranged around follicular openings
thin grey circles
angulate lines- polygons (rhomboids)
annular granular pattern
What is the mimic or LM?
Pigmented AK - can have exactly the same features
Which pattern is most specific for early LM? (MIS)
Circles - 30% of all lesions with circles turn out to be MIS
Why do 14% of MIS contain reticular or curved lines?
These are collision structures - SL
Which pattern is most specific for solar lentigo?
Structureless
Curved lines
Reticular lines
Why reticular lines in SL?
Rete ridges regrow
Do one or two circles make a melanoma?
No, not if overall pattern = SL
What is accuracy of grey on face?
Highly sensitive, will not miss melanoma.
Not specific.
50% SL has grey
Majority of MM has grey
Most specific pattern for AK?
White circles
Scale
4 dots in square - polarized dermatoscopy
(May have any pattern)
Why reticular lines in PAK?
Collision lesions
What % PAK have scale?
1/3
What % PAK have white circles
2/3
Can white circles be present in other lesions?
Yes, e.g. BCC
Sensitive of 4 dots in square for AK
Not sensitive or specific.
Can be found in normal skin
Dermoscopy of mucosal lesions
Brown - likely benign
Any Grey, Blue, White, r/o malignancy
Are AK usually pigmented
No
Non pigmented AK typical
Scale
Erythematous background
Hypopigmented follicular openings
White circles are clue
Significance of AK + prominent vessels
Consider that the lesion is already invasive
AK, prominent vesses, management
Biopsy. Do not treat with liquid n2.
Common mutations AK and SCC
P53
How many AK regress spontaneously?
Most
Patient with > 20 AK have ? Risk developing SCC
20% increased risk
Which lesions of AK should we treat?
All
Ulcerated red nodule Ddx
Amelanotic melanoma
SCC, poorly diff
Merckle Cell Ca
Metastasis
Features seb gland hyperplasia
Vessels not as sharp
Vessels do no cross centre
White clods in centre correspond to seb glands.
Arborizing vessels are produced by …
any tumour that grows underneath superficial vascular plexus.
White globules/ structureless areas in lesions could be …
Keratin - usually also on surface
Fibrosis (particular pattern) - usually associated white lines
Pus
Necrosis
Pilomatricoma
Nodule
White structures - Produces hair like substance - white under dermatoscope
Bleeding
Discoid lupus erythematosis dermoscopy features
Perifollicular Whitish halo - may resemble white circles Erythematous background my resemble Follicular keratitis plugs Telangiectatic vessels - non specific White scales Pigmentation Structureless white areas Follicular red dots
Pilomatricoma characteristics
Benign adnexal neoplasm
Common in children
Any age
Rapid growth
Discoid lupus erythematosis characteristics
Inflammatory condition
Usually on chronically sun exposed skin
Discoid lupus erythematosis Ddx
Need to distinguish from dermatitis/ Bowen’s disease.
