Simple cryosurgical treatment of the oral melanotic macule ScienceDirect Pigmentation Document Gale Academic OneFile Happy Wednesday! , In this video, a patients labial melanotic macule (a benign pigmented lesion) is being treated with liquid nitrogen. Labial melanotic macules are flat and asymmetrical with a Brown spots, especially on the lips, can be alarming to some. In some instances it can indicate rare oral mucosal melanoma, however in this case it was a non cancerous labial melanotic macule.