1. Thirty-five year-old male bilateral proptosis.
WEEKLY RADIOLOGY QUIZ-243
LAST WEEK’S CASE
Prize: Bird watching field guide
Answer: Thyroid ophthalmopathy
Thirty-five year-old male bilateral proptosis.
Correct answers: 4
Winner: Adnan Bilik
Enlarged bellies of both medial recti
Axial CT slice
In thyroid ophthalmopathy, or thyroid-associated orbitopathy (TAO), antibodies against TSH receptors cause lymphocytic infiltration and fibroblastic proliferaion in retro-orbital tissues which result in proptosis as well as restricted eye movement. Of the extraocular muscles, the inferior and medial recti are involved most frequently. Typically, the belly of the muscle enlarges, while the tendons taper normally. The involvement is often bilateral and symmetrical. Most commonly associated with Graves disease.