Symptomatic empty sella syndrome: an unusual manifestation of Erdheim-Chester disease.

Erdheim–Chester disease (ECD) is a potentially fatal condition characterized by infiltration of multiple organs by non-Langerhans histiocytes. Although endocrine dysfunction has been reported in association with ECD, to date, there have been no previous reports of empty sella syndrome (ESS) associated with it. We report the case of a patient with ECD who had symptomatic ESS. A 55-year-old man of Chinese ethnicity initially presented with symptoms of heart failure, fatigue and knee joint pain. Physical examination revealed xanthelasma, gynaecomastia, lung crepitations, hepatomegaly and diminished testicular volumes. He had laboratory evidence of hypogonadotrophic hypogonadism, secondary hypoadrenalism and GH deficiency. Imaging studies showed diffuse osteosclerosis of the long bones on X-ray, a mass in the right atrium and thickening of the pleura and of the thoracic aorta on fusion positron emission tomography–computed tomography. Magnetic resonance imaging (MRI) of the brain showed an empty sella. The diagnosis of ECD was confirmed by bone biopsy. Learning points ECD is a multisystemic disease that can affect the pituitary and other organs. The diagnosis of ECD is based on clinical and radiological features and histology, showing lipid-laden CD68+ CD1a− S100− histiocytes surrounded by fibrosis. The finding of xanthelasmas especially in the presence of normal lipid levels in the presence of a multisystem infiltrative disorder should raise the suspicion of ECD. Systemic perturbation of autoimmunity may play a role in the pathogenesis of ECD and is an area that merits further research.