basal cell carcinoma
"I used this on a persistent basal cell carcinoma, in the centre of my forehead, which never healed and bleed at times, on application ,nothing happened much for a week, but then my face erupted right across my forehead, large red blotches which turned to blisters.   
I  used it for three weeks instead of six weeks as recommended.  I went to  my doctor who said to stop using it.  The scabs soon cleared, and after a short while my skin was clear and back to normal.  Was it worth it?Most definitely, no carcinoma, in the UK it's a prescription drug and only available through a doctor, and paid for by our NHS so I don't know the cost."