Spinal manifestations of Paget's disease: Case presentation and systematic review.

Introduction: Paget's disease of the bone (PDB) is a chronic disorder characterized by abnormal bone remodeling, often involving the spine. Although spinal stenosis and neural compression are well-documented manifestations, facet joint synovial cysts in PDB are extremely rare, and their development remains unclear. Research question: We report the case of a PDB patient who presented with progressive radicular symptoms due to an enlarged L1-L2 cyst with marked facet hypertrophy and stenosis. Materials and methods: We presented a case of a patient who underwent surgical decompression along with cyst excision, during which a thick-walled, hemorrhagic cyst compressing neural structures was identified. Postoperative neurological function exhibited enhancement. To compare with this case, we performed a systematic review adhering to PRISMA guidelines regarding spinal complications associated with PDB, encompassing ten articles and a cumulative total of 87 patients. Results: The most frequently reported manifestations included spinal stenosis, vertebral fracture, spinal cord compression, cauda equina syndrome, and neurological deficits. The literature only referred to one reported case of synovial cyst in relation to PDB. Discussions and conclusion: This article and case highlight that, while uncommon, facet joint synovial cysts belong in the correct differential diagnosis of the spinal manifestations of PDB, particularly when there is neural compression. Impeccable imaging and customized surgical planning are significant in the management of such complex cases.