Multidisciplinary treatment of a rare rapidly progressive intracranial myxoid mesenchymal tumor of uncertain differentiation FET-CREB fusion-negative.

Background: Non-meningothelial intracranial mesenchymal tumors are a heterogeneous group of central nervous system neoplasms endowed with great variability clinically and histologically. For this precise reason, significant difficulties exist in specifically cataloguing tumor entities with such distant characteristics and such uncertain clinical course.

Case description: In an attempt to increase the knowledge inherent in this type of central nervous system lesions we report a case of a rare and unusual myxoid mesenchymal tumor of difficult anatomopathological classification characterized by rapid progression and optimal therapeutic response after combined surgical and radiotherapy treatment, with histo-molecular definition and DNA methylation profile. In this case, multidisciplinary management led to timely surgical intervention based on the rapid clinical deterioration and radiological progression; after adjuvant therapy with hadron therapy, the patient has no signs of recurrence two years after the surgical procedure. No FET-CREB fusion was detected, and the DNA methylation profile suggested the presence of multiple chromosomal gains and losses.

Conclusions: The molecular definition as well the optimal therapeutic regimen of these tumors is not clearly defined yet and analysis of larger series is strongly warranted.