Sellar xanthogranuloma in a dog.

Area of Science:

• Veterinary Pathology
• Comparative Pathology
• Canine Endocrinology

Background:

• Hypothyroidism and atypical hyperadrenocorticism are common endocrine disorders in dogs.
• Sellar region masses can cause significant neurological dysfunction in canines.
• Xanthogranulomatous inflammation is a rare but recognized inflammatory process.

Observation:

• A 7-year-old intact male Standard Poodle presented with acute lethargy, vomiting, diarrhea, and neurological deficits including hind limb proprioception loss and obtundation.
• The dog exhibited behavioral changes such as aggression and an equivocal seizure.
• Necropsy identified a sellar region mass with extensive cholesterol clefts, multinucleated giant cells, macrophages, and Rosenthal fibers, obscuring pituitary tissue.

Findings:

• Histological examination of the sellar mass revealed features consistent with xanthogranuloma.
• The findings closely resemble xanthogranuloma of the sellar region and xanthogranulomatous hypophysitis described in human medical literature.
• Absence of identifiable pituitary tissue suggests complete destruction or displacement by the inflammatory mass.

Implications:

• This case highlights a rare cause of neurological disease in dogs, presenting similarly to human sellar region xanthogranulomas.
• Accurate histopathological diagnosis is crucial for understanding the pathogenesis and potential treatment of such sellar masses.
• Further research into canine xanthogranulomatous hypophysitis may improve diagnostic and therapeutic strategies for similar conditions.