By A. Vaglio

 

In addition to the retroperitoneum, ECD can affect several organs or tissues: it may involve the retro-orbital tissues, with exophtalmos; the skin, with frequent “xanthoma-like” lesions, xanthelasma and pruritic rash; the lung, with frequent interstitial infiltration and fibrosis and pleural thickening or effusions; the pericardium, with pericardial effusions; finally, it may also affect the pituitary and hypothalamic axis, often leading to diabetes insipidus 6.

However, bone disease is typically found in ECD patients and symmetrical osteosclerosis of the long bones is considered to be the only specific radiological sign of the disease 4. In ECD the epiphyses of the long bones and the axial skeleton are usually spared, although exceptions have been described; the most commonly affected bones are the femur, tibia and fibula and less frequently the ulna, radius and humerus 7.

On the basis of the above literature data and of the patient's complaint of bone pain, we performed a whole-body skeleton X-ray, which showed marked osteosclerotic lesions affecting the femur, tibia and fibula (Figures 3A, 3B), thus confirming the diagnosis of ECD.

Figure 3A	Figure 3B

We also screened for other potential sites of disease by means of appropriate radiological studies, but no other involved organs or tissues were found.

Although the clinical course of the disease can range from benign to malignant/aggressive, the outcome of ECD patients is usually grim and may depend on the extent and distribution of extraosseous involvement 4. At present, there is no staging system for ECD and no clear prognostic factors have been identified. In the largest published review (59 cases), it was reported that 22 (59%) of 37 patients with follow-up had died of the disease, and the most frequent causes of death were respiratory distress due to lung involvement and heart failure 4.

QUESTION 3