Metastatic melanoma posing as periapical pathology: key features and learning points British Dental Journal Rare malignant melanotic nerve sheath tumors of the upper limb nerves: utility of high frequency ultrasonography in preoperative imaging Skeletal Radiology Springer Nature Link Epithelioid malignant peripheral nerve sheath tumor Applied Radiology Malignant melanotic nerve sheath tumor with PRKAR1A, KMT2C and GNAQ mutations Peripheral nerve tumor Wikipedia