Primary leptomeningeal melanocytic tumors of the spine: report of two cases and review of the literature.

Primary leptomeningeal melanocytic tumors of the central nervous system are rare and especially in the spine less frequent compared to other entities. There is no consensus regarding the best care of these tumors. We report two cases of primary leptomeningeal melanocytic tumors, one PLM (Primary Leptomeningeal Melanoma) and one PLMC (Primary Leptomeningeal Melanocytoma) of the upper cervical spine and emphasize different surgical findings and clinical courses of these patients. A review of the literature according to primary leptomeningeal melanocytic tumors of the spine was done, especially to compare different treatment modalities in the younger history. Primary melanocytic tumors of the spine are exceedingly rare. Prior to surgery it is difficult to make a correct diagnosis. Usually an unexpected intraoperative finding with consecutive histopathological analyses lead to the final diagnosis. An accurate search for melanocytic tumors outside the CNS as primary source is mandatory. PLMC have a better prognosis than PLM. There is no consensus regarding the adjuvant therapy, but PLM patients should be given radiotherapy, chemotherapy and immunotherapeutical approaches as immune checkpoint blockade after surgery. Communicating hydrocephalus is highly associated to PLM, but may occur in PLMC as well.