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

Abstract

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.

Talus Avascular Necrosis as a Rare Complication of Cushing’s Disease: A Case Report

“…As far as we are aware, this case presentation represents the first instance of AVNT attributed to Cushing's disease in the existing literature. Nevertheless, some individuals with endogenous Cushing's syndrome have been reported to experience AVN of the femoral head [4][5][6][7][8][9][10][11][12].…”

“…[3] The use of glucocorticoids is one of the most important non-traumatic causes of AVN. Nevertheless, there are some case reports where AVN in the femoral head is reported as a manifestation of endogenous hypercortisolism, particularly associated with Cushing's syndrome [4][5][6][7][8][9][10][11][12].…”

A rare case of multifocal osteonecrosis of the femur in a heart transplant patient

“…Whilst the pathogenesis of AVN in cardiac transplantation remains incompletely understood, it is hypothesized that the high doses of corticosteroids used in immunosuppression play a major role [1,17] . Proposed theories include corticosteroid induced adipose hypertrophy, fat embolism, hypertension and atherosclerosis [17][18][19] .…”

“…Whilst the pathogenesis of AVN in cardiac transplantation remains incompletely understood, it is hypothesized that the high doses of corticosteroids used in immunosuppression play a major role [1,17] . Proposed theories include corticosteroid induced adipose hypertrophy, fat embolism, hypertension and atherosclerosis [17][18][19] . However, both Bradbury et al and Lieberman et al showed no relationship between the peak or cumulative dose of Prednisone received and the development of AVN in cardiac transplant patients [7,20] .…”

Patient on Multiple Hormone Replacement Therapy for Hip Arthroplasty: How to Omit Noise and Be Focused?

“…The treatment of choice is selective pituitary resection including medical management, radiation therapy, and bilateral adrenalectomy [4]. Avascular necrosis is seldom seen as a part of initial case presentation due to endogenous hypercortisolism, but usually, AVN is a complication of prolonged glucocorticoid therapy [5,6]. Patients on chronic steroid therapy may develop adrenal insufficiency because of surgical stress that may lead to a full-blown adrenal crisis in the perioperative period.…”