Intradural tumor recurrence after resection of extradural metastasis: a rare but potential complication of intraoperative durotomy.

Spinal metastases are the most common of spinal neoplasms and occur predominantly in an extradural location. Their appearance in an intradural location is uncommon and is associated with a poor prognosis. Cerebrospinal fluid dissemination accounts for a significant number of intradural spinal metastases mostly manifesting as leptomeningeal carcinomatoses or drop metastases from intracranial tumors. The occurrence of local tumor dissemination intradurally following surgery for an extradural spinal metastasis has not been reported previously. The authors describe 2 cases in which local intradural and intramedullary tumor recurrences occurred following resection of extradural metastases that were complicated by unintended durotomy. To heighten clinical awareness of this unusual form of local tumor recurrence, the authors discuss the possible etiology and clinical consequences of this entity.