Current management of central nervous system metastasis from cholangiocarcinoma: the neurosurgical perspective. Literature review.

Purpose: Central nervous system (CNS) metastasis from cholangiocarcinoma (CCA) are extremely rare and associated prognosis is poor. The involvement of the CNS by metastatic CCA may discourage any further treatment; however, data from the literature are discordant, due to recent reports of exceptionally long follow-up after surgical resection of a brain metastasis. Material and Methods: Electronic databases, such as PubMed/MEDLINE and Google Scholar, were analyzed for studies published up to October 2018 using the search term "cholangiocarcinoma and central nervous system metastasis or brain metastasis". Results: We found a total of 18 studies cited in the literature of the 30 year span analyzed, and we added a new case we treated at our Institution, reaching a series of 32 patients. Among these, 7 patients had leptomeningeal dissemination and 25 presented solid CNS metastasis. We analyzed the treatment options and the outcomes, addressing also histopathological insights on tumoral markers possibly involved in the mechanism of metastases of cholangiocarcinomas Conclusions: According to the literature data, the outcome remains poor, particularly for those with leptomeningeal diffusion. Nevertheless, long term follow-up is reported in case of surgical resection of CNS metastasis, when there is a good control of the primary tumor. Actually, the majority of patients are often in advanced state of disease at diagnosis and not suitable for initial resective procedure; in these cases neo adjuvant and adjuvant therapies have provided a slight improvement of the outcome.