Nail melanoma Flashcards
Evaluating melanonychia striata requires inspection of the nail plate, cuticle, paronychium and hyponychium
True
Pigment on any of the cuticle, paronychium, hyponychium in association with melanonychia striata is highly suggestive of melanoma
True
Hutchinson or Micro-Hutchinson sign is a melanoma specific feature of nail unit melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Hutchinson sign is defined as pigmentation of the proximal mail fold that can be seen with the naked eye
True
Micro-Hutchinson sign is defined as pigmentation of the proximal nail fold that can only be seen with Dermoscopy
True
In contrast to Micro-Hutchinson sign, Pseudo-Hutchinson sign is the reflection of pigment in the nail matrix visible through relatively translucent cuticular skin, and has no diagnostic significance
True
Pigment on the hyponychium should be evaluated in the same manner as for acral melanoma.
True
Pigmentation on the hyponychium with a parallel ridge pattern would be highly suggestive of melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Hyponychial pigment with acral melanoma specific feature is suspicious for melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Hyponychial pigment is defined as irregular pigmentation on the distal periungual skin
True
Triangular shape pigmentation of the nail plate is a melanoma specific feature for nail unit melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Triangular shape pigmentation is defined as width of the melanonychia striata wider at the proximal end of the nail plate
True
An irregular band pattern is a melanoma specific feature of nail unit melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Irregular band pattern is defined as multiple, longitudinal, irregular bands of different colours(I.e. black, brown, grey) with irregular spacing, thickness, and disruption of parallelism
True
Nail dystrophy is a melanoma specific feature of nail unit melanoma
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Nail dystrophy is defined as complete or partial nail destruction, and/or absence of the nail plate
True
The features of nail unit melanoma are: Hyponychial pigment with acral melanoma features Hutchinson or Micro-Hutchinson sign Triangular shape Irregular band pattern Nail dystrophy
Examination of the melanonychia striata includes measurement of the width of the nail plate pigmentation at both the proximal and distal ends of the nail plate
A wider diameter at the proximal end resulting in a triangular shape is suggestive of rapidly growing tumours including melanoma
Examination of the melanonychia striata should include evaluation of the individual striations/bands
Benign lesions are characterised by a regular parallel pattern with parallel lines spaced at regular intervals with minimal variation in colour or thickness. Colour of the lines tend to get lighter towards the lateral edges.
Melanomas have an irregular pattern with multiple longitudinal lines of differing colours (I.e. brown, black, grey) and thickness, with irregular spacing and disruption of parallelism
Benign nail unit lesions have regular parallel pattern with:
parallel lines spaced at regular intervals
minimal variation in colour or thickness
Colour of the lines tend to get lighter towards the lateral edges
True
Nail unit melanomas have an irregular pattern with:
multiple longitudinal lines of differing colours (I.e. brown, black, grey) and thickness
irregular spacing
disruption of parallelism
True
DDx for longitudinal melanonychia
Trauma
Infection
Melanocyte activation (drug induced pigmentation, lentigo, PIH)
Melanocyte proliferation (naevus, hyperplasia, melanoma)
Pigment granules within pigmented nail band = melanocyte proliferation
Absence of pigment granules = melanocyte activation
Melanocyte activation = Absence of granules within a greyish coloured band
Melanocyte proliferation = Brown to black bands, pigment granules within the band, multiple prominent linear lines within the band
Regular pigmented band = benign
Brown = naevus Grey = lentigo (pigmented keratinocytes)
Irregular pigmented bands = melanoma
Multiple coloured lines (black, brown, grey)
Variation in thickness of lines
Variation in spacing of lines
Loss of parallelism
Dermoscopy of the free edge of the nail plate -
Increased pigment upper part = proximal nail matrix melanocytic lesion
Increased pigment lower part = distal nail matrix melanocytic lesion
