The technique of micrographic surgery (MOHS) was developed by Frederick Mohs in the 1930s. Doctors use this method to remove skin tumors while examining the borders of the tumor during the surgical procedure.

Doctors using the MOHS technique attempt to remove as little facial tissue as possible in order to minimize cosmetic damage and functioning.

The tumor borders are marked by ink and examined, while the surgical wound remains open

If pathological findings show that no malignant tissue remains in the borders of the tumor, the wound can be closed. If findings show malignant tissue in the border area, surgeons perform a wider removal of tissue from the marked area, which is marked and examined again, and the procedure is repeated. Only when pathological examination showed that the entire tumor has been removed will the surgeons close the wound. This technique ensures that the entire tumor, and no more, is removed.