Melanotic schwannoma mimicking metastatic pigmented melanoma: a pitfall in cytological diagnosis Project One NYC Metastasis Network 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 An 84 year old man with a history of metastatic melanoma of the scalp who was undergoing immunotherapy presented with new, multiple blue gray macules on the scalp.