Spontaneous resolution of avascular necrosis of femoral heads following cure of Cushing's syndrome

Spontaneous bone infarction of the distal femur in a patient with Cushing's disease: a case report

Avascular necrosis of the femoral head is a well-known complication of treatment with high dosage glucocorticoids and has been described in a few patients with Cushing's syndrome. In this case report, we describe the, to our knowledge, first case of a patient with endogenous Cushing's syndrome with a bone infarction located in the distal femur. In patients with Cushing's syndrome and bone pain, the diagnosis of bone infarction should be considered as it can occur as a rare complication of hypercortisolism.

Avascular femoral necrosis as part of Cushing syndrome presentation: a case report

Background

The clinical characteristics and complications of Cushing syndrome (CS) are well known and described in the literature. Nevertheless, rare, atypical presentations may go unnoticed. Osteonecrosis is a well-documented complication of glucocorticoid therapy. However, endogenous hypercortisolism is a rare, but relevant, cause of bone avascular necrosis. We describe the case of a woman with CS undiagnosed for 2 years after presenting with femoral avascular necrosis.

Case presentation

A 38-year-old Caucasian woman was referred for evaluation of secondary amenorrhea, associated with oral contraception withdrawal in the context of deep venous thrombosis (DVT). She had a previous right hip arthroplasty for treatment of avascular necrosis of the femoral head, diagnosed after 3 years of progressive right hip pain and limited mobility. She also had high blood pressure (HBP) of 5 years’ duration, and reported weight gain (4 kg in 2 years). There was no history of infertility (gravida 2, para 2). Physical examination revealed buffalo hump, truncal obesity, facial plethora, muscular atrophy and proximal myopathy, and easy bruising (under anticoagulant treatment for DVT). Workup showed abnormal overnight dexamethasone suppression test (DST) (serum cortisol 21.5 µg/dL; normal < 1.8 µg/dL), elevated 24-hour urinary free cortisol (UFC) (728.9 µg/day; reference range 36.0–137.0 µg/day), and suppressed plasma adrenocorticotropic hormone (ACTH) (< 1.0 pg/mL), findings consistent with ACTH-independent CS. Urinary metanephrines and catecholamines were normal, and the remaining analytical study showed no major changes, apart from glycated hemoglobin (HbA1c) of 6.8%. Adrenal computed tomography (CT) scan showed a 25 mm lesion in the left adrenal gland, with density non-suggestive of adenoma. The patient underwent unilateral adrenalectomy and started steroid replacement. Histology revealed an adrenal cortex adenoma. Three months after surgery the patient presented with resolution of HBP and hypercortisolism (UFC 37.4 µg/day; reference range 36.0–137.0 µg/day).

Conclusion

In some cases, CS signs may go unnoticed and the diagnosis postponed. Avascular necrosis is a rare presenting feature of endogenous hypercortisolism, and, if left untreated, complete collapse of the femoral head may ensue, rendering the need for hip replacement in up to 70% of patients. Suspicion and recognition of atypical features is therefore important in avoiding complications and delay in treatment of CS.

Avascular necrosis of the femoral head: An exceptional complication of cushing's disease

Avascular necrosis (AVN) of the femoral head is a well-recognized complication of steroid treatment. Exogenous glucocorticoids' administration and alcoholism are the most common nontraumatic etiologies. AVN secondary to endogenous hypercortisolism (HC) is rare; very few case reports are available on this complication. We describe a 28-year-old female that has presented an AVN with Cushing's syndrome. Biochemical investigations confirmed HC. Magnetic resonance imaging (MRI) showed a pituitary adenoma that was resected transsphenoidally. The postoperative failure directed to radiosurgery treatment. Then, the patient then expressed a significant clinical improvement while developing adrenocorticotropic deficiency; hence, steroids were indicated. During the discovery of Cushing disease, the patient presented also limping and progressive pain in right hip. The pelvis MRI showed an AVN of the right femoral head. The patient underwent a total replacement of the right hip sine presenting an extensive AVN. This case elucidates that AVN could be an early manifestation of Cushing's disease.

Bilateral osteonecrosis of the hip in panhypopituitarism

Osteonecrosis, also known as avascular necrosis, is a condition that causes significant morbidity and loss of function. It is a common complication seen with supraphysiological steroid use. Early diagnosis is critical as it impacts prognosis. We report a 20-year-old man who developed bilateral osteonecrosis of the hip following 6 years of low-dose steroid replacement therapy for panhypopituitarism secondary to a transsphenoidal resection of a growth hormone-secreting pituitary macroadenoma. The patient presented with several weeks of right-sided hip pain and significant loss of function. X-ray and MRI showed bilateral osteonecrosis of the hips with the right side more severely affected than the left. He was initiated on analgesics and bisphosphonates and underwent right hip total arthroplasty followed 1 year later by left hip arthroplasty. Postsurgery, the patient is mobilising well and his pituitary hormones are well balanced. He continues on low-dose glucocorticoid replacement which will continue lifelong.