Onset of rheumatoid arthritis after surgical treatment of Cushing's disease.

We describe a patient with Cushing's disease who, shortly after trans-sphenoidal surgical resection of an adrenocorticotropic hormone secreting pituitary microadenoma and specifically at the time of normalization of her serum cortisol level, developed a subacute episode of symmetric polyarticular synovitis. This episode lasted for one month; however, it did not resolve completely and progressed after 3.5 years of diffuse arthralgias and morning stiffness to seropositive and erosive rheumatoid arthritis (RA). Review of the literature revealed 3 additional patients with RA with a similar course. These patients may represent a natural illustration of the antiinflammatory effects of supraphysiological levels of endogenous glucocorticoids.