Intracranial meningioma in a pet rat: MRI findings

Area of Science:

• Veterinary Neurology
• Diagnostic Imaging
• Comparative Oncology

Background:

• Intracranial neoplasms are a concern in pet rats, though less commonly reported than in other species.
• Magnetic Resonance Imaging (MRI) is a crucial diagnostic tool for evaluating brain lesions in animals.

Observation:

• A 1.5-year-old pet rat presented with neurological signs including depression, ataxia, tremors, and nystagmus.
• A 0.25 T MRI scan was performed to investigate suspected intracranial neoplasia.
• The MRI revealed a well-defined, oval, extra-axial mass with heterogeneous, hyperintense T1 and T2 signal, causing severe brain compression.

Findings:

• The mass demonstrated strong and diffuse contrast enhancement.
• Necropsy confirmed a voluminous extra-axial mass.
• Histopathological examination diagnosed a well-differentiated, benign meningotheliomatous meningioma, with histochemical stains ruling out granular cell tumor.

Implications:

• This case represents the first reported MRI investigation of an intracranial meningioma in a pet rat.
• The findings highlight the utility of MRI in diagnosing brain tumors in rodents.
• This report contributes to the understanding of meningioma occurrence and imaging characteristics in companion animals.