Orbital involvement in Erdheim-Chester disease.

Erdheim-Chester disease is a rare, idiopathic, non-Langerhans' cell, histiocytic disorder. To our knowledge this is only the second case of Erdheim-Chester disease reported in the Chinese population. We describe a 45-year-old woman presenting with unilateral proptosis and periorbital xanthelasma. Histopathological examination revealed a xanthogranulomatous lesion expressing CD68, but negative for S100 protein, CD1a, CD3, or CD20. Systemic involvement was evident on bone scanning, and involvement of the thorax and abdominal aorta was seen on computed tomography. Despite treatment with systemic steroids, immunosuppressants, chemotherapy and interferon, progressive deterioration occurred. Our patient's clinical course was consistent with reports in the literature. Unfortunately, our patient developed neutropenic fever and died from septicaemic shock. Although Erdheim-Chester disease is a rare entity, especially in the Chinese population, an unusual presentation with orbital masses and bilateral xanthelasma, associated with systemic features, should raise the suspicion of this serious and potentially fatal disease.