This lesion is a BCC on the eyelid which required a wedge excision.  Note the fine branched blood vessels that are typical of a BCC    Histology - Superficial BCC completely excised - Phew!!

This lesion is on the scalp and has developed since I examined his skin 6/12 ago.  The pattern is curved lines. The colour is brown changing to grey and the grey area is starting to become structureless.  The clinical context gives the clue here because this lesion is developing in a scar.  The maturing scar tissue is probably the cause of the appearance of this lesion which is likely to be a Solar Lentigo.  I have done a punch biopsy sample and will let you know the results later.   Histology - Solar Lentigo in a scar

This is a new lesion on the lip  that has been growing over the past three months.  The pattern is brown clods.  The clinical is very helpful with this case because the areas with the brown colour are raised with a cystic appearance that is typical of a BCC  Histology - nodular BCC

Last interesting case for today
This is on the shoulder of an elderly gentleman.  The pattern is reticular with thickened lines. The right side of the lesion is losing its reticular pattern and we are seeing grey polygons developing with one area of grey structureless melanin.  Initially you could be tempted to call this an ink spot lentigo and it may well have been that initially.  This lesion was removed completely after discussing the options of a punch sample or a shave biopsy.   Will let you know what it turns out to be   Histology - Solar Lentigo

This lesion has a uniform reticular network peripherally. Centrally there are some skin coloured clods surrounded by  symmetrical structureless blue /grey pigmentation.
The reticular network peripherally is reassuring and a pattern of clods centrally means that with better visualisation of the lesion we would probably see that the blue/ grey area is probably made up of clods as well. This lesion is probably changing from a Solar lentigo into a Seborrheic Keratosis.  If this lesion has been present for months to years then  it is safe to see in 3/12 for another picture. If it is new and changing then the best option is a shave biopsy.

The same description can be applied to this one
This lesion has a uniform reticular network peripherally. Centrally there are some skin coloured clods surrounded by  symmetrical structureless blue /grey pigmentation.
The reticular network peripherally is reassuring and a pattern of clods centrally means that with better visualisation of the lesion we would probably see that the blue/ grey area is probably made up of clods as well. This lesion is probably changing from a Solar lentigo into a Seborrheic Keratosis.  If this lesion has been present for months to years then  it is safe to see in 3/12 for another picture. If it is new and changing then the best option is a shave biopsy.

One pattern of red and black Clods - Haemangioma

One pattern of Red and Black CLods = Haemangioma

One pattern of Red and Black CLods = Haemangioma

Is this a pigmented lesion ?
This is a scabies mite. The head of the mite is at 12 o'clock. Look hard!!

This pigmented lesion has a pattern of dark brown clods that are evenly distributed on a uniform brown background.  The border is sharply defined and the lesion stands out from the skin and has been present for a long time.  This is called a Unna Nevus and is benign.

This lesion is on the eyelid of a marathon runner.   
The pattern  is reticular dark brown with sharply demarcated borders.
This is a Solar Lentigo

Here is another  one , Young guy with many moles , first time Ive seen him


Another good example.
Pattern first  - this is a reticular pattern 
Colour  next- one colour ( the brown pigment varies in density only) 
When scanning the skin , ONE pattern and ONE colour means it is benign and you move on to the next lesion.
There are other features that make it benign  - symmetrical / uniform pattern around the periphery / central hyperpigmentation
Now after all the description we can add a label  - Clarks Nevus.  
Remember that brown pigment is in the epidermis in Keratinocytes predominantly - they collect it from Melanocytes.

I am not sure i f this photo is of sufficient quality but I’s be interested in your thoughts . It stood out on the back of a 57 yr old woman
I was concerned that is was a reasonable  size , had an irreg asymmetrical borer and a darker colour in the centre


This is a great case Alistair and excellent for the start of this Blog.
It highlights the way the algorithms of pattern analysis can quickly lead to a probable diagnosis.

Pattern Analysis consists of Pattern assessment followed by Colour assessment followed by Clues.  Always remember PCC  - pattern colour clues  - I will be drumming this message on every blog!!! The order is the order of importance - pattern colour clues.  Pattern is defined by pigment.


This case has a reticular pattern peripherally so immediately many diagnoses have been eliminated.  You will also notice that there is chaos within the lesion - highly significant


There is more than one colour   - brown blue and grey.  The significance of blue and grey is that it means the melanin is in melanocytes in the dermis rather than melanin in keratinocytes in epidermis where the colour is brown and black. Grey and blue together are highly likely to be associated with Melanoma.
So you can see grey at 2, 9 and 11 o'clock as well as centrally where you can see some blueness as well.


Now to the clues  - 

• blue/grey structures centrally
  
• eccentric structureless areas
• thickened reticular lines

You are now in a position to make a probable diagnosis of Melanoma that is likely to be in situ.
So when you write to the histopathologist you are in a position to confidently say that Dermatoscopically this IS a Melanoma in situ at the least.  This means that the histopathologist will take more slices and look more carefully.  Even if the report from the histopathologist was not Melanoma in situ, this lesion should be treated as such - ie 5mm margin on initial removal at the least.