Lower extremity insufficiency fractures: an underappreciated manifestation of endogenous Cushing's syndrome.

This report describes the presence of lower extremity insufficiency fractures in 10 women prior to the clinical and biochemical diagnosis of endogenous Cushing's syndrome (CS). Osteoporosis is a well-recognized complication of overt CS resulting in a high rate of vertebral and other fractures. After institutional review board (IRB) approval, we did a retrospective chart review of patients with lower extremity (LE) insufficiency fractures (IF) and CS. This chart review found 10 women in whom LE-IF preceded the diagnosis of endogenous CS. Low bone density was found in all but one patient. The CS was considered to be mild (or subclinical) in five patients. LE-IF should be considered part of the skeletal spectrum of CS. Physicians caring for patients with LE-IF should have a low threshold for the consideration of CS even in patients without overt physical evidence of cortisol excess.