Abstract 196: Non traumatic avascular necrosis of hip – A rare atypical presentation of Cushing's disease

Background: Avascular necrosis (AVN) is a well-recognized complication of exogenous glucocorticoid therapy. However, it is extremely rare in endogenous hypercortisolemia. We describe a case of young man with pituitary macroadenoma and ACTH dependent Cushing's syndrome presenting with avascular necrosis of femoral head. Case Presentation: A 24-year male presented to orthopedics department with non-traumatic progressive pain in left hip and difficulty in walking for last 2 years. This was associated with weight gain of 20 kg over 3 years along with easy bruisability, development of purple stria over abdomen, proximal muscle weakness and recurrent fungal skin infections. On evaluation in orthopedics, his X-ray and MRI of left hip confirmed AVN of femoral head for which surgery was planned. In presurgical evaluation he was found to have diabetes mellitus and hypertension for which he was referred to Endocrinology department. Patient denied receiving any oral or injectable exogenous steroids. Physical examination confirmed clinical stigmata of Cushing syndrome along with hyperpigmentation of skin, knuckles, and toes. His investigations revealed hypokalemia, hyperglycemia (HbA1C 9%), elevated morning serum cortisol (33 mcg/dl) along with high plasma ACTH of 288 pg/ml. His serum cortisol failed to suppress on low dose and high dose dexamethasone, thereby confirming endogenous ACTH dependent Cushing's syndrome. MRI brain revealed large invasive pituitary macroadenoma for which he was subjected to trans nasal tumor resection. For medical management of Cushing's, ketoconazole was started and titrated. On follow up patient has marked regression of his symptoms and is now planned for surgery of hip AVN. Conclusion: This case illustrates that Cushing's disease may rarely present with AVN to Orthopedics. Missing the signs and symptoms of hypercortisolemia while focusing on management of AVN may lead to delay in diagnosis and management of this life threatening disorder.