Mucosal melanocytic macules Treatment of labial melanotic macules on the lip. These are benign spots that appear on the lips for no apparent reason. The causes are mostly genetic, but similar spots can appear in smokers, after Pigmented Lesions of the Oral Mucosa Springer Nature Link Pigmented (Purple or Brown) Lesions in the Mouth melanotic macule Archives Kazemi Oral Surgery Facialart.com Mara Ever wondered what those little brown spots are that are often found on the lip? Many refer to them as a freckle but the medical term is melanotic macules.