Oral melanotic macule and primary oral malignant melanoma: Epidemiology, location involved, and clinical implications Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics 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 An 84 year old man with a history of metastatic melanoma of the scalp who was undergoing immunotherapy presented with new, multiple blue gray macules on the scalp. Oral Melanotic Macule MEDizzy