I noticed a lump on my back whilst in the bath last night - thought it might be a spot, but on checking when I got out of the bath I saw it was raised dark brown almost black lump. 
 

I called the GP this morning and was seen first by an advanced practitioner in the morning and then asked back to be seen by a GP in the afternoon who specialises in dermatology.

They had a look by eye at first and said it could be dermatofibroma. They looked closer using a dermascooe and as it is pigmented and has a very darkened centre under the dermatascope they no longer suspect dermatofibroma. GP measured the lump as 7mm lesion on the lower back, raised, and smooth to touch.

I have now been referred as a 2week fast track referral for suspected skin cancer (in their words).

I am worried and wondered if anyone has any experience of this.

I am mixed white and black Caribbean and quite dark skinned. The GP said it's much rarer for people of colour to get skin cancer. I do not have a family history of skin cancer and do not spend lots of time in the sun (certainly don't have my top off exposing my back - and do use sun cream elsewhere).