Endocrine Abstracts

Avascular necrosis is a rare presenting feature of endogenous hypercortisolism. The literature suggests that, if left untreated, complete collapse of the femoral head may ensue, necessitating hip replacement in up to 70% of patients. The majority of described patients with avascular necrosis due to endogenous hypercortisolaemia were treated surgically.

Case report: A 36-year-old female, investigated for right leg pain, reported rapid weight gain, easy bruising and secondary amenorrhea. She had abdominal adiposity with violaceous striae, facial plethora and hirsutism, atrophic skin, ecchymosis and proximal muscle weakness. Spinal imaging showed L4/L5 disc herniation, fractures of L1 and multiple ribs. Investigations confirmed cortisol excess (cortisol post low dose 48-h dexamethasone suppression test 807 nmol/l; 24-h urinary free cortisol 1443 nmol (normal<290 nmol)). ACTH was <5.0 pg/ml. CT demonstrated subtle left adrenal gland hypertrophy. Post left adrenalectomy hypercortisolaemia persisted. Histology revealed primary pigmented micronodular adrenal disease. Post-operatively right leg pain worsened and left leg pain developed, affecting mobility. MRI showed bilateral femoral head avascular necrosis, which was not surgically treated at this point. She underwent right adrenalectomy and commenced steroid replacement. Within 4 months of surgery her leg pain resolved and she could ambulate freely. Repeat MRI showed marked improvement in high signal intensity in both femoral heads, consistent with spontaneous healing of avascular necrosis.

Conclusion: We report a case of a 36-year-old woman with Cushing’s syndrome due to primary pigmented nodular adrenocortical disease, presenting with symptomatic avascular necrosis of both hips. This was managed conservatively from an orthopaedic perspective. Following cure of hypercortisolaemia, the patient experienced an excellent functional and radiological recovery. She remains symptom-free 4 years post adrenalectomy. This case is the first to report a favourable outcome over long-term follow up of a patient with bilateral avascular necrosis of the hip which reversed with treatment of endogenous hypercortisolaemia.