inside cheek Keyword Search Science Photo Library Pigmented (Purple or Brown) Lesions in the Mouth Pigmented (Purple or Brown) Lesions in the Mouth Kazemi Oral Surgery Facialart.com What Causes Black Lump Inside Mouth? Liv Hospital ORAL MELANOTIC MACULE (OMM) (Also called focal melanosis labial melanotic macule) A benign, localized, flat pigmented lesion of the oral mucosa Caused by a focal increase in melanin production