2011 Radiology Exam - Musculoskeletal Case 2

Signalment: 6 year old male/c Doberman Pinscher
History: Progressive pelvic limb ataxia

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Observation ‐ Lateral and ventrodorsal spinal images centered at the midthoracic, thoracolumbar, and midlumbar regions. Focused images centered at the caudal lumbar spine provided at request.
• Lysis of the right transverse process of L5 with extension of lytic process into the body of L5

Aggressive lesion involving the L5 vertebra.
Differential diagnosis:
• Primary bone tumor of the spine
• Metastatic bone tumor
• Soft tissue neoplasm invading bone
• Infectious process – much lower diagnosis

• Biopsy of L5
• Thoracic radiographs to evaluate for metastasis
• Bone scintigraphy

Unsuccessful candidates failed to recognize the L5 lesion.