Enhanced melanoma and non melanoma skin cancer classification using a hybrid LSTM CNN model Scientific Reports 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. Frontiers The WHO 2018 Classification of Cutaneous Melanocytic Neoplasms: Suggestions From Routine Practice Rare Forms of Melanoma and Melanocytic Tumors IntechOpen