Melanotic Macule.  A freckle on the lip.   The lower lip is more often the site where a melanotic macule is found.  It is simply due to sun exposure and is painless, but constant.  It does not fade in color or come and go.

The Melanotic Macule can also be found on the gum tissue inside the mouth, on the palate of the mouth, or in the cheek area (buccal muscosa).  To be sure that it is not pre-cancerous or cancerous, it can be biopsied to exclude the diagnosis of malignant melanoma.  Once the biopsy report  shows Melanotic Macule, there is no treatment recommended.

Prevention would be to keep a lip balm with Sun Protective Factor (SPF) on your lips at times that you are in the great outdoors.  Once the Melanotic Macule has developed, lip balm will not cause it to vanish or to diminish.