Standardized Clinical Assessment of Patients With Leptomeningeal Metastasis

Inclusion Criteria: * Adult patients (18 years or more), female or male * Histologically confirmed diagnosis of extra-CNS primary solid cancer * Diagnosis of leptomeningeal metastases confirmed or probable per EANO ESMO criteria * Performance status compatible with enrolment into clinical trials * Ability to consent * Signed informed consent form from patient * Participation in a parallel clinical trial is allowed in this non-interventional study Exclusion Criteria: * Inability to give informed consent * Inability to adhere to recommended follow-up according to the treating physician Vulnerable participants will not be included.