A para aortic malignant melanotic nerve sheath tumor mimicking a gastrointestinal stromal tumor: a rare case report and review of literature BMC Surgery Springer Nature Link Improving our Understanding of the Management and Pathogenesis of Rare and Neglected Tumors of the Central and Peripheral Nervous System Frontiers Research Topic Decoding Melanoma Metastasis Stage 4 of Metastatic Melanoma Skin Cancer, Prognosis, Treatment, Follow up Care MRA