A case of Erdheim-Chester disease with orbital involvement.

The Erdheim-Chester disease is a rare idiopathic, systemic, histiocytic disorder. To our knowledge, ocular involvement has been reported in only 16 cases. We describe a 55-year-old man who had symmetrical exophthalmos and several skin nodules on the arms and trunk. A magnetic resonance imaging scan confirmed the presence of bilateral, intraconal, retrobulbar tumors. An examination of the histopathologic features of orbital and skin biopsy specimens revealed xanthogranulomatous infiltrate with Touton giant cells. Further systemic investigations showed bone and retroperitoneal involvement. Three years later, multiple eyelid xanthelasmas developed in the patient. These findings are consistent with the diagnosis of the Erdheim-Chester disease. The patient's condition is stable under therapy with low-dose corticosteroids. His survival is longer than usually described in the literature.