Occult intrasacral meningocele: case report and review of the literature

Occult intrasacral meningocele, characterised by the presence of a cyst within the sacral spinal canal, is an unusual congenital lesion. A 26-year-old female presented with a history of low back pain and sensory disturbance in the lower extremities, and urinary incontinence. CT scan of the sacral region showed an asymmetrical widening of the sacral canal and the existence of a thinned bone contour. Magnetic resonance (MR) imaging revealed an intrasacral mass as a low signal intensity area on the T1-weighted image and a high signal intensity area on the T2-weighted image, suggesting a cyst containing cerebrospinal fluid (CSF). The patient underwent sacral laminectomy and posterior exploration showed the presence of sacral erosion and an intrasacral cyst containing CSF devoid of neural contents. Partial surgical excision of the cyst was carried out, but the patient's postoperative course was complicated by a CSF leak due to a small connection that was obliterated in a second operation. Control MR imaging confirmed the removal of the cystic lesion. The clinical, neuroradiological and surgical features of this rare condition are discussed and the importance of a differential diagnosis is stressed.