Melanotic nerve sheath tumor of the gasserian ganglion and trigeminal nerve A Rare Case of Aggressive Melanotic Schwannoma Occurred in Spinal Nerve of a 59 Year Old Male Post operative Stereotactic Radiosurgery of Malignant Melanotic Schwannoma Cureus A Rare Case of Epithelioid Malignant Peripheral Nerve Sheath Tumor Mimicking Malignant Melanoma Cureus Frontiers Cervical Malignant Melanotic Nerve Sheath Tumor with retained PRKAR1A expression and a clinically benign course: a case report and review of the literature