Spinal drop metastases from a papillary meningioma: a case report and review of the literature: utility of CSF sampling.

In this paper, we report a rare case of a 29-year-old boy who presented with papillary meningioma originating from the posterior fossa meninges. After a long, disease-free period, however, spinal drop metastases occurred 32 months after resection of the primary tumor. The primary and metastatic lesions had a similar histological appearance, meaning that multiple spinal metastatic lesions occurred through CSF route even after a gross total resection of the tumor. Tumor seeding during surgery is the evident reason for spinal metastasis, although we strictly adhered to the standard precautions for operations for malignant tumors such as obstruction of the cisterna magna with cotton paddies, and changing surgical gloves and instruments during the operation. In this report, we briefly discuss an exceedingly rare variant of meningioma, the papillary variant, and suggest a new approach, a CSF sampling, in the management of both malignant and benign meningiomas. CSF sampling allows for the early detection of metastasis and of tumor cells before metastasis has occurred, thus allowing treatment to begin as soon as possible. This early detection and management is possibly associated with longer survival. Furthermore, we discussed that meningiomas are tumors that are not as benign as initially thought.