Lumbar facet cyst tuberculosis: a rare cause of cauda equina compression. Illustrative case

BACKGROUND: Spinal tuberculosis may present in atypical form to involve only the posterior spinal element with relative sparing of the anterior vertebral body and intervertebral disc. Recognition of this unusual pattern is important to avoid delay in diagnosis and treatment. OBSERVATIONS: The authors report a case of a 59-year-old woman with right-sided radiculopathy and motor weakness. Her lumbosacral magnetic resonance imaging showed a large heterogeneous cyst arising from the right L4–5 facet joint. Laminectomy with excision of the cyst was performed. During surgery, the cyst contained cheese-like material that, on histopathological examination, revealed focal aggregates of tuberculous granuloma. Postoperatively, the patient recovered remarkably with no interval development of instability or any deformity. LESSONS: Facet cyst tuberculosis is rare but should be considered in the differential diagnosis in patients coming from endemic regions. Laminectomy with excision of the cyst along with concurrent antitubercular chemotherapy is a safe and durable treatment option in this case.