Ask the doctor: What is Mohs surgery?

Q. My dermatologist is recommending Mohs surgery to remove a basal cell cancer on my nose. What does this involve?

A. Mohs micrographic surgery is named after Frederic Mohs, who developed the technique in the 1930s. It's a specialized surgical procedure used to eliminate skin cancers that spread locally (but do not spread through the body) and are likely to return unless all the cancer is cut out. The goal of Mohs surgery is to remove all of the cancer cells while preserving as much of the normal tissue as possible. To do this, the surgeon removes the cancerous tissue layer by layer, examining each layer under a microscope, until the outer edge of the removed layer (the margin) is free of cancer cells.