Abstract 7P
Background
Εxtraneural metastases (ENM) do not occur often with central nervous system (CNS) tumors (only 7% of cases) due to the existing blood- brain barrier (BBB) and lack of classic lymph drainage. They are usually found in cases of a prior surgery or biopsy. In 1955 the minimal criteria that had to be met in order for a metastasizing CNS tumor to be accepted as such, were proposed by Weiss. Tumors of the posterior fossa are usually associated with higher operative mortality compared to supratentorial tumors, due to increased intracranial pressure and Abraham and Chandy in 1963 proposed the use of a ventriculoperitoneal shunt (VPS) to surpass this danger. Medulloblastomas in particular often render a VPS necessary for symptom relief.
Methods
We searched electronic databases using combinations of the terms “central nervous system tumors”, “CNS tumors” “ventriculoperitoneal shunt”, “VP shunt”, “medulloblastomas”, “adults”, “extracranial metastasis”. We included patients older than 18 years of age. Quantitative analysis was conducted.
Results
Our research revealed 11 published cases of extracranial metastasis due to a VPS in adults with CNS tumors (Table) and 3 published articles regarding 5 patients in total, in those with medulloblastoma. Table: 7P
| Author | Patient’s age (years) / Gender (man / woman / other) | CNS malignancy |
| Bridges K | 34 / man | Hemangiopericytoma |
| Ng JJ | 36 / man | Rhabdoid meningioma |
| Ingold B | 45 / woman | Atypical teratoid/ rhabdoid tumor |
| Yasuhara T | 47 / woman | Glioblastoma |
| Araki M | 53 / woman | Anaplastic ganglioglioma |
| Rickert H | 24 / man | Cerebral teratocarcinoma |
| Kim K | 36 / man | Primary pineal germinoma |
| T S Talamo | 25 / man | Primary intracranial germinoma |
| Haimovic I C | 27 / man | Germinoma |
| Pasquier B | 21 / woman | Malignant astrocytoma |
| Chen F | 62 / man | Primary CNS lymphoma |
Conclusions
In adult patients, extracranial metastasis due to a VPS are rare in CNS tumors and even more rare in cases of medulloblastoma compared to the paediatric population group. It is important due to the rarity of these cases that each one is documented. There needs to be a high level of clinical suspicion that metastasis due to a VPS might take place.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.