Pigmented Lesions of the Central Nervous System: Radiologic Pathologic CorrelationRadioGraphics Malignant melanotic nerve sheath tumors in the spinal canal of psammomatous and non psammomatous type: Two case reports Metastatic melanoma After the immune system destroys melanoma tumors, visible melanin can be left behind. We tracked tumoral melanosis in a case series of patients on immunotherapy and offer suggestions for how to monitor