Erdheim Chester disease: a rare cause of knee and leg pain.

A case of Erdheim Chester disease in a 51-year-old Turkish patient is described. Erdheim Chester disease is a rare form of lipoid granulomatosis. Knee and leg pain are the most common symptoms, and physicians working in orthopaedics and traumatology are the first to be consulted. Our patient demonstrated a typical bilateral, symmetric sclerosis of the metaphyseal region of long bones of the lower extremity, histologic examination revealed foamy, lipid-loaded histiocytes. The patient also suffered from arterial hypertension, diabetes insipidus and exophthalmos of the left eye. The diagnosis was confirmed by a bone biopsy, and the patient was treated with non-steroidal anti-inflammatory drugs, corticosteroids and vincristine.