Primary intraspinal tumors shows little or no tendency of hematogenous spreading. Distant metastases in other organs are therefore extremely rare.
Very occasionally, ependymomas can spread via cerebrospinal fluid and create remote metastases in the craniospinal space.
Around 5–15 % of all patients with cancer will experience symptom-producing spinal/epidural metastases. The spreading is hematogenous and the majority of spinal metastases originate from cancer of the:
In very rare cases, intracranial tumors can metastasize into the spinal canal. In such cases the spreading has occurred through the flow of cerebrospinal fluid, and the secondary tumors are located in the subarachnoidal space, known as "drop metastases". This applies to medullablastomas and germinomas, amongst others.