Cervical spinal inflammatory myofibroblastic tumour in a 3‐year‐old dog (Canis lupus familiaris)

A 3‐year‐old, female, spayed cross‐breed dog presented with a history of progressive right‐sided hemiparesis and cervical hyperesthesia. The neurological examination results were consistent with a C1–C5 myelopathy. Magnetic resonance imaging revealed an extradural mass located along the vertebral body of C4 in a right lateral position, causing dislocation and compression of the spinal cord. The preliminary diagnosis was a neoplastic lesion. An infectious‐inflammatory lesion was considered to be a less likely differential diagnosis. A right‐lateralized dorsal laminectomy was performed, providing spinal cord and lesion visualization, which was subsequently excised. Histological and immunohistochemical examinations revealed an abnormal proliferation of spindle cells associated with marked multifocal lymphoplasmacytic infiltration, consistent with an inflammatory myofibroblastic tumour. Normal gait was restored within 3 months from surgery and the patient did not exhibit signs of pain in the subsequent months. Follow‐up magnetic resonance imaging did not show signs of recurrence of the lesion 1 year after surgery.