Clinical spectrum of histiocytic tumors of the orbit

Histiocytic tumors of the orbit comprise an unusual group of lesions characterized by the infiltration of the orbital tissues by xanthomatous cells. Recently, there have been a number of new observations regarding the various histiocytic tumors that can affect the orbit. The condition previously referred to as histiocytosis X is believed to represent a proliferation of Langerhans cells and the term Langerhans cell histiocytosis is often used instead of histiocytosis X. Juvenile xanthogranuloma has been demonstrated to affect the orbit without involving the skin or the iris. The Erdheim-Chester disease is a condition of adults characterized by infiltration of bone, retroperitoneum, heart, lungs and other tissues by xanthoma cells. This condition has recently been recognized to produce a classic ophthalmological picture of bilateral xanthelasmas and bilateral proptosis. The authors review their personal experience with several patients with histiocytic tumors of the orbit and stress the clinical spectrum of these conditions.