LAUSR

Abstract Background: Increased fat deposition is a hallmark of exogenous and endogenous hypercortisolism (Cushing’s syndrome, CS). Fat accumulates not only in the abdomen and liver, but also in unusual locations such as the temporal and supraclavicular fossae, intrascapular fat pads and spinal epidural space (1). Here we describe, to our knowledge, the first report of intracapsular fat deposition at the hip in a patient (pt) with CS. Case Presentation: A 47 year old African American male presented with a six year history of diabetes and hypertension. He also reported abdominal weight gain, moodiness, facial flushing, blurry vision, fatigue, joint aches (especially knee and hips), muscle weakness leading to falls, difficulty with ambulation, straie, and decreased memory. Physical exam on admission revealed a rounded face with bitemporal fat pads, supraclavicular and dorsocervical fat pads, central obesity, +1 pitting edema of the lower extremities, 4/5 strength in shoulders and hips, ankle flexion and hand grip strength 5/5, wide violaceous striae on the abdomen. Biochemical evaluation revealed urine free cortisol 1460.8 and 1031.2 mcg/24h (ref: 3.5-45 mcg/24h), and plasma ACTH levels of 51.3-158 pg/ml (ref:5-46pg/ml). Pituitary MRI showed an 8mm lesion, CRH stimulation test showed 52% increase in cortisol level (29.8 to 43.1 mcg/dl) and a 79% increase in ACTH level, (95.9 to 175 pg/ml), suggestive of Cushing’s disease. However, cortisol increased by 41% after 8mg dexamethasone (23.2 to 32.8 mcg/dL), and IPSS also was consistent with an ectopic source of ACTH. A 10mm right hilar lesion was identified by CT, MRI, and 68Ga-DOTATATE. While awaiting surgical resection, pt was treated with ketoconazole and metyrapone. Three weeks after initiation of medical therapy, pt reported new unprovoked bilateral hip pain with antalgic gait. MRI hip revealed only bilateral symmetric intracapsular fat abutting the superolateral aspects of the femur in the subcapital region. There was no evidence of avascular necrosis of bone, osteoarthritis, or collagen tear. Physiatry evaluation reported functional hip strength in the 4- range, hip extension bilaterally 2+, unchanged ability from a prior admission to stand from sitting position without the use of upper extremities, and ability to ambulate independently across a room, but necessary use of a single point cane for longer distances. Physical therapy noted a decline in his mobility status since last visit, and recommended use of a wheeled walker. Discussion: This is the first time we have identified a patient with increased fat in the hip joint explained by no other comorbidities other than Cushing’s Syndrome. This new finding adds another unusual location for increased adipose in the clinical presentation of patients with CS. Further studies are needed to better assess the correlation between the finding of intracapsular hip fat, pain and hypercortisolism.