This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thyroid, Subject name: Medicine
Proptosis not seen in? 
Select and explain. 
A. Primary thyrotoxicosis, B. Sarcoidosis, C. Pituitary adenoma, D. Hypothyroidism
D: Hypothyroidism
Answer: D: Hypothyroidism 
Explanation: Ans. 'd' i.e. Hypothyroidism Eve involvement in Grove's disease (Graves ophthalmophathy)o The wide eyed stare and proptosis due to:-# Increased sympathetic tone# Infiltration of orbital soft tissue and extra ocular muscles with lymphocytes.# Mycopolysaccharides and edema fluids.Causes of proptosisa) Bilateral Proptosis1) Endocrine exophthalmos due to dysthyroid eye disease.2) Cavernous sinus thrombosis3) Metastatic neuroblastoma4) Orbital myositis (due to causes other than thyroid dysfunction).b) Unilateral Proptosis1) Haemangioma2) Dermoid cyst3) Lymphangioma4) Rhabdomyosarcomac) Transient Proptosis1) Arterio-venous malformations2) Orbital varices