I have a growth about two-three inches above my knee which started as a small, flat growth. I scratched it, and it began to grow like a pimple the size of a BB pellet. Within a four week period, it has grown to the size of an oval dime, not perfectly round. It itches, is extremely sore to the touch, has prickly sensations, and even aches a bit. I have an appointment with a dermatologist this Tuesday. It is red around the growth where it itches (more at night). Any insights as to whether basal cell or squamous cell?