Intraspinal collision tumor comprising a schwannoma and ependymocytoma: a rare case study and literature review.

Collision tumors, a rare phenomenon wherein two tumors with different histological features appear in the same anatomical region, present a challenging clinical diagnosis, particularly in the context of intraspinal collision tumors. This study reports the clinical data of a patient with an intraspinal collision tumor composed of schwannomas and ependymomas. A 47-year-old woman was admitted to the hospital with a six-month history of lumbosacral pain and numbness in both lower extremities. Lumbar magnetic resonance imaging (MRI) revealed two space-occupying lesions in the L1-2 spinal canal, which were initially diagnosed as two separate neurogenic tumors. Subsequent pathological examination revealed a collision tumor comprising a schwannoma and ependymoma. Intraspinal collision tumors, especially those combining schwannoma and ependymocytoma, are exceedingly rare. When two separate or conjoined tumors are present at the same anatomical site, the possibility of a collision tumor should be considered, despite its rarity. Interestingly, it was found that vertebral collision tumors tend to involve hemangiomas, whereas intraspinal collision tumors predominantly involve schwannomas.