USE OF I-123 METAIODOBENZYLGUANIDINE SCINTIGRAPHY FOR THE DIAGNOSIS OF A PHEOCHROMOCYTOMA IN A DOG

A 13-year-old neutered female Yorkshire terrier presented with a history of progressive episodic weakness and disorientation of 4 months duration. Physical and neurologic examinations were normal at presentation. Abdominal ultrasound revealed a mass involving the right adrenal gland. Standard planar scintigraphy was performed at 4, 18, and 24 hours after intravenous injection 185 MBq (5 mCi) of I-123-labeled metaiodobenzylguanidine (I-123-MIBG). An area of focal intense uptake was identified in the area of the right adrenal gland. A pheochromocytomma was confirmed histologically after surgical excision.