Simultaneous L1-2 Bulged Disc and Mobile Spinal Schwannoma Causing Cauda Equina Syndrome: A Rare Case Report

BACKGROUND Aside from the rarity of mobile spinal schwannomas, the coexistence of these tumors with herniated intervertebral disc is also scarce. Furthermore, cauda equina syndrome (CES), as a manifestation of intraspinal schwannomas has been reported rarely. Described here is a case of simultaneous lumbar disc bulge and mobile spinal schwannoma presented with intermittent symptoms of CES. CASE REPORT A 62-year-old man presented with severe but intermittent leg pain for 2 weeks, which later progressed to an episode of lower extremity weakness and difficulty in urination. Magnetic resonance imaging revealed an intraspinal tumor that moved in position relative to the L1-2 disc bulge on scans 6 h apart, with associated spontaneous regression in symptoms. The tumor was found to be a mobile spinal schwannoma, originated from a nerve root. A standard microdissection technique was used to remove the tumor through a spinous process-sparing unilateral approach, with complete laminectomy of L1. Use of intraoperative ultrasound facilitated the accurate tumor localization. Postoperatively, the patient no longer had symptoms. CONCLUSIONS This report presents a combination of a common spinal pathology, intervertebral disc herniation, alongside a rare condition, mobile spinal schwannoma, whose uncommon clinical manifestations, such as CES can cause irreversible neurological deficits. Surgeons need to remain vigilant of potential atypical scenarios when treating patients. Surgical treatment challenges regarding the mobility of tumors, such as accurate localization, should be addressed using intraoperative imaging to avoid wrong-level surgery. To mitigate the irreversible neurological complications, patients should receive comprehensive information for alarming signs of CES.