IMAGING DIAGNOSIS-CONCENTRIC PERIRADICULAR LIPOMA CAUSING LUMBAR NERVE ROOT COMPRESSION IN A DOG

An 11-year-old, male neutered Jack Russell Terrier was presented with a nerve root signature of the right pelvic limb. Magnetic resonance imaging revealed a well demarcated, ovoid, extramedullary mass at the level of the L7 vertebral body. This showed, compared to normal spinal cord, hyperintense signal on T1- and T2-weighted images, which was suppressed on gradient echo short tau inversion recovery (GE-STIR) images. Additionally, the mass was characterized by a fat density on computed tomography images. Histopathology of the surgically excised mass was consistent with concentric periradicular lipoma, which has not been described in domestic animals yet.