Cerebriform appearance of flat seborrhoeic keratoses
A learner in my clinic last week had dermoscoped a seborrhoeic keratosis (seb k for short, otherwise known as basal cell papillomas) but wasn’t quite sure as ‘I can’t see a cerebriform appearance.’ Good point to make. I replied that while a classic cerebriform appearance (in the new descriptive terminology that is ‘lines broad parallel curved’) is a strong pointer to a seb k, it is a superficial structure. As the lesion thickens, the flat cerebriform appearance is superimposed upon by 3-dimensions structures like milia like cysts and comedo like openings, or else a keratinised fissured surface.
Seborrhoeic keratoses have a wide range of recognised features and you will almost never see all the classic features in the same lesion. It is not for nothing that they make up such a huge proportion of the harmless skin lesions referred urgently as suspected skin cancers.
I have been tidying up old images on my netbook and will post some seb k images over the next month to show the wide range of presentations. Half of all practical dermoscopy, for the GP and practice nurse at least, is ruling out seb ks as benign. If that was all that the dermoscope ever achieved, it would be well worth while.
A patient presented with this pigmented lesion on the face. It is somewhat variable in shape and colour. It violates the ABCD rule to some extent. Dermoscopy is interesting.
It almost looks like 2 different lesions, but I believe it to be just one.
On the left we see a typical cerebriform (brain like) pattern pf gyri and sulci. In the new Kittlerian descriptive terminology this would be broad lines parallel and curved‘ but as Iris Zalaudek said in the debate at Vienna, pleading the case for the old fashioned terminology where appropriate, the term ‘cerebriform’ is fewer syllables and well understood. The best of the old terms will be defined and retained, to the bests of my understanding, when the promised new dermoscopy dictionary is published.
On the right of the lesion we see a thicker seb k with numerous milia like cysts (white clods) and a few comedo like openings (brown clods). Its all seb k, just of different thickness. These lesions start out flat, and their morphology changes somewhat randomly as they get thicker. It’s not that difficult a concept to understand.
I will post a few more seb ks over the next month. No apology for this: they can be very easy but evidently not for everyone as s many still get mistaken for life threatening melanomas and referred urgently.