Reverse pigment network
This proven melanoma shows a reverse pigment network as well as blue grey veil and irregular peripheral globules.
I was reminded on the reverse (or negative) pigment network sign last week at an excellent presentation in London By Dr Jonathan Bowling and Oxford colleague Dr Ben Esdaile and Dr Andy Affleck from Dundee, both keen dermoscopists. The advanced dermoscopy day conference was arranged by the Primary Care Dermatology Society a dermatological education charity with which I have the privilege of being involved as a trustee and committee member, although this blog is independent of them. Dr Bowling, who is acknowledged as the UK’s top dermoscopy teacher, reminded us about this sign which may appear early or late in the evolution of a melanoma. Early on, it may be the only sign. A key point of his teaching was that skin lesions do not appear fully formed, they emerge and develop gradually. Dermoscopy with the right knowledge and experience can help us make the diagnosis at an earlier stage, saving money, costlier treatment for more advanced disease, and perhaps lives.
This sign used to be called ‘irregular scar like pigmentation’ and as far as I can tell is not analogous to the reticular pigment network of benign naevi. It is fairly specific for melanoma, especially in the presence of other signs. It is the milky lacework that runs between the brown, throughout the whole lesion. I believe it is the same as what was called the ‘spilt milk sign’ although I haven’t heard that term used for a few years now.
This histologically proven melanoma also shows a blue grey veil centrally and irregular peripheral globules. The reverse network can be seen throughout the lesion. Dr Bowling said it could be the only dermoscopic feature of a new changing lesion, although clearly it is easier to make the diagnosis the more positive features for melanoma are present.
The PCDS runs Dermoscopy For Beginners day courses around the country, see linked web site for details. We also run advanced days usually once a year but may do more due to growing demand. We also work with international experts Giuseppe Argenziano and Iris Zalaudek, both of whom can be seen on YouTube.