Rash found to be sinister on biopsy

It is scaly with small erosions and mild crusting. However, it has been present for two years, steadily increasing in size and not responding to antifungal creams or topical steroids.

A history like this demands biopsy to find out what is going on. Two punch biopsies were taken from different parts of the lesion and both showed squamous skin cancer in situ, i.e. the cancer was all confined to the epidermis. Excising this would involve a skin graft to close the defect as it also extended into the web space.

It was decided to use 5-fluorouracil