title: Malignant degeneration of an epithelial nevus vs porokeratosis with malignant change.
mesh_terms: D006801:Humans; D007642:Keratosis / Q000150:complications / Q000175:diagnosis*; D009506:Nevus / Q000150:complications / Q000175:diagnosis*; D012871:Skin Diseases / Q000209:etiology; D012878:Skin Neoplasms / Q000209:etiology*