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Objective: To report the clinical and MRI features, and histologic findings of thoracolumbar discal pseudocyst in dogs. Materials and Methods: The records of eight dogs with thoracolumbar discal cyst‐like structures were retrospectively collected to record their clinical signs, MRI features and surgical and histologic findings. Results: Eight dogs with surgically and histologically confirmed thoracolumbar discal pseudocysts were included in the case series. Six dogs presented with acute onset and two dogs presented with subacute onset of thoracolumbar myelopathy. MRI showed compressive thoracolumbar myelopathy due to a round to oval‐shaped epidural mass lesion communicating with the intervertebral disc, iso/hypointense on T1WI and mostly hyperintense on T2WI, associated with a variable contrast‐enhancing wall, compatible with a cyst‐like structure. These structures were surgically visualised and removed through a mini‐hemilaminectomy or hemilaminectomy and submitted for histologic investigation. One dog also underwent cytologic examination of the cystic content. Similar to that in humans, histology revealed a cyst‐like nature with a wall consisting of dense fibrous connective tissue containing clusters of chondroid cells accompanied by groups of notochordal cells and occasional erythrocytes; however, a real epithelial lining was missing and the term pseudocyst seemed more appropriate. Clinical Significance: This report describes clinical signs, and MRI and histologic findings of discal pseudocysts in dogs with thoracolumbar myelopathy. Despite being rare, discal pseudocysts should be considered as a differential diagnosis in dogs with acute onset thoracolumbar myelopathy. [ABSTRACT FROM AUTHOR]

Objectives To report the clinical presentation, magnetic resonance imaging features, treatments and outcomes of canine vertebral chondrosarcoma. Materials and Methods Retrospective review of medical records of dogs with confirmed vertebral chondrosarcoma and magnetic resonance imaging of the lesions, from four different veterinary referral institutions. Results A total of six dogs were included in this report. In all cases, magnetic resonance imaging revealed a lobulated mass involving the dorsal vertebral compartment, markedly hyperintense with few foci of hypointensity on T2-weighted images, iso to hypointense on T1-weighted images with contrast enhancement after gadolinium administration. Intralesional surgical resection was performed in three dogs and medical management in one, two dogs were euthanased and all lesions were submitted for histopathology. Magnetic resonance imaging findings correlated with histological findings of a low tumour grade. Rapid clinical improvement was noted after surgery but two of three dogs had local regrowth. Clinical Significance Chondrosarcomas show local aggressiveness and resistance to conventional radiotherapy and chemotherapy, and so prognosis depends on feasibility of en bloc resection. Magnetic resonance imaging may be helpful in establishing a presumptive diagnosis and prognosis based on the feasibility of surgical resection. [ABSTRACT FROM AUTHOR]

A cat with a history of seizures and clinical suspicion of forebrain disorder underwent a brain magnetic resonance imaging. A space-occupying lesion was identified in the left temporal lobe. The mass was surgically removed, and cytological, histological and immunohistochemical examinations documented the presence of Toxoplasma gondii. A definitive diagnosis of an intracranial T gondii granuloma was made. The cat was treated with clindamycin and phenobarbital and the seizures did not recur. After 10 months, a second magnetic resonance imaging showed severe brain atrophy, but T gondii granuloma recurrence was not noted. Twenty-one months after surgery, the cat’s condition deteriorated, and another magnetic resonance imaging showed a presumptive recurrence of T gondii granuloma. In cats, T gondii granuloma must be considered as a differential diagnosis even when only a single intracranial mass is present. Cytology and magnetic resonance imaging can be useful in making a definitive diagnosis and to follow the evolution of the lesion. [ABSTRACT FROM AUTHOR]