Exophthalmos is typically associated with Graves' ophthalmopathy. Although originally described by Harvey Cushing, exophthalmos is an underappreciated sign of Cushing's syndrome. We present a case of a 38-year-old female who presented with severe bilateral proptosis and was subsequently diagnosed with Cushings disease. We discuss the possible mechanisms causing exophthalmos in patients with either endogenous or exogenous hypercortisolemia.
A 38-year-old female noticed progressively worsening bilateral proptosis for a period of two years, to the point causing episodes of ocular dislocation from her sockets. She also noted irregular menstrual cycles during this time and was amenorrheic for 6 months prior to referral. She underwent extensive workup by her primary care physician including thyroid tests which were normal. She then underwent orbital decompression surgery in June 2011 with transient improvement of symptoms. However in the next 12 months she gained 60 lbs and developed proximal muscle weakness, purplish abdominal striae, facial hirsutism, and easy bruisability. She was also diagnosed with new onset diabetes and hypertension during this time and was treated with Metformin and Lisinopril, respectively. Physical examination revealed an obese female with a BMI of 43 and BP
Bilateral exophthalmos as seen on MRI.
MRI of pituitary (coronal view) (arrows showing the macroadenoma and stalk deviation).
Histology: (a) H&E stain showing basophilic cells at magnification
Exophthalmos or proptosis refers to forward displacement of the eyeball. It has to be differentiated from retraction of the eyelids, which can cause an illusion of exophthalmos. Conventionally, exophthalmos refers to ocular proptosis secondary to endocrinopathies. Graves’ disease is the most common endocrine cause of exophthalmos. Although described in 1932 by Harvey Cushing in 4 of his 12 patients with Cushings disease, this is an often forgotten clinical sign [
Exophthalmos is seen in about 30–45% of patients with Cushings syndrome (CS) [
The cause of exophthalmos in CS is still unknown. Multiple theories have been proposed including fat redistribution and increased retro-orbital fat, associated thyroid disease, and an exophthalmos causative factor. It has been proposed that retro-orbital fat deposition is also part of the fat re-distribution seen in CS, resulting in increase in volume of the retro-orbital tissues and a consequent rise in intra-orbital pressure [
The authors report no conflict of interests.