Spinal extradural meningioma mimicking lumbar disc herniation in a cat: a case report

Neoplasia affecting the feline spinal column is an uncommon clinical occurrence, with the most frequently documented types being lymphosarcoma, osteosarcoma, glial tumors, and meningioma. This report describes the first case of an extradural meningioma affecting the lumbar spinal cord of a cat. An 8-year-old spayed female domestic shorthair cat presented with a two-day history of paresis, dyschezia, and reduced tail movement. Hematologic testing and thoracic radiographs revealed no abnormalities; however, lumbar radiography identified a radiopaque mass in the spinal canal at the L5-6 level. Magnetic resonance imaging demonstrated an extruded nucleus pulposus-like extradural mass with limited parenchymal enhancement, compressing the spinal cord at L5-6. A hemilaminectomy was performed, and an extradural soft tissue mass not attached to the dura mater was excised. Histopathology confirmed the diagnosis of a fibrous meningioma. While spinal meningiomas typically present as intradural extramedullary lesions, their occurrence in the extradural space is exceptionally uncommon, especially when no dural connection is present. This case provides the first imaging description of an extradural fibrous meningioma without dural involvement in a cat. Clinically, this highlights the importance of considering atypical forms of meningioma in the differential diagnosis of extradural spinal masses with minimal contrast enhancement.