Case Report: Spinal intramedullary fungal granuloma: clinical findings, surgery, and outcome in a dog

A 7-year-old male neutered Miniature Schnauzer was assessed due to an acute and progressive history of pelvic limb weakness and incoordination. At the examination, the dog was non-ambulatory paraparetic, the postural reaction were abscent in both pelvic limbs, with intact withdrawal and patellar reflexes and increased pelvic limb muscle tone, which lead into paraplegia with intact nociception in the follow 24 h. A T3-L3 myelopathy was suspected, and an MRI of the thoracolumbar vertebral column was performed under general anaesthesia. An ill-defined, solitary, T2W hyperintense and strongly contrast enhancing intramedullary lesion was found, extending from the caudal endplate of T12 to the midbody of T13 and associated with severe spinal cord oedema and meningeal enhancement. A lumbar CSF analysis revealed a severe mononuclear pleocytosis (309 cells/μL) and markedly increased protein level; serology against Neospora caninum and Toxoplasma gondii was negative, and treatment with steroids for a suspected focal meningomyelitis of unknown origin was started. The patient deteriorated over the following days, becoming paraplegic with reduced nociception in the right pelvic limb. An exploratory surgery was carried out via T12-T13 right-sided hemilaminectomy, durotomy and myelotomy, and a well-defined, firm intramedullary mass was removed and sent for histopathology. The mass was consistent with an inflammatory pyogranuloma with intralesional fungal hyphae. Panfungal PCR was negative. Treatment with fluconazole was started, and a follow-up MRI was performed 6 months after surgery. At this time the dog was ambulatory paraparetic and MRI revealed complete resolution of the previous mass. Repeat CSF analysis revealed a mild mononuclear pleocytosis (6 cells/μL) and a mild increase in protein. Fluconazole treatment was continued for another 12 months; during all this time, the patient remained ambulatory with a mild paraparesis. The patient died for unrelated reasons 18 months after surgery when under general anaesthesia for routine removal of a subcutaneous lipoma.