Tattoos may conceal skin cancers
More and more men and women are getting tattoos, sometimes very large and dark ones. There is no evidence, or reason to suppose, that tattoos increase the risk of a skin cancer (although there have been reports of infections) but if people are unlucky enough to get a skin cancer under a tattoo, it may make diagnosis more difficult.
This image shows part of a large tattoo, something was noted at the edge of it. This picture is not very well focused, but shows an area of slightly abnormal skin that presented as it was scabbing slightly. A skin lesion that scabs and never heals over 3 weeks or more may be a basal cell cancer (BCC). The lesion is indistinct, let’s get the dermoscope on it to see if we can discover any more detail.
The area blanches under pressure from the glass plate of the dermoscope, revealing a quite different texture to the surrounding normal skin. A few compressed blood vessels near the centre of the image can just be seen. but the most striking features are the blue-grey clods (or globules) in the bottom left, which vary considerably in size and shape. These are also known as blue grey ovoid nests, and are very typical of BCC. To the right, we see a micro ulcer, the well defined irregular red clod. This is ample to diagnose a BCC, which was confirmed on histology after the lesion was removed.
The blue-grey colour at the top of the picture is tattoo ink, which happens to be a very similar colour to the blue-grey clods seen in BCC. Once again, the dermoscope takes a rather nondescript skin lesion and enables us to make a positive diagnosis by revealing detail the naked eye cannot see.
The moral of the story is, tattoos can make skin cancers more difficult to diagnose. In this case it didn’t matter but if you had a melanoma come up under a dense black area of tattoo ink, it might grow for longer than it might otherwise have done before being spotted. I have seen a melanoma come up in a gap in a dark tattoo-lucky it came up in the gap and was caught early.