Unusual orbital involvement in Erdheim Chester disease: a radiological diagnosis

Abstract

Erdheim-Chester disease (ECD) is an exceedingly rare, disseminated non-Langerhan cell histiocytosis with multisystem involvement, having characteristic sclerotic skeletal lesions. We present an unusual case primarily manifesting as an extensive orbital disease, with low-grade systemic involvement. Owing to its rarity and therefore lack of general awareness it remains a difficult clinical and pathologic diagnosis. Immuno-histochemistry of the biopsy specimen is diagnostic.