Bilateral orbital Erdheim-Chester disease treated with 12 weekly administrations of VNCOP-B chemotherapy: a case report and a review of literature.

Erdheim-Chester disease (ECD) is a non-Langerhans' cells histiocytosis of unknown etiology, which generally presents with long bones involvement, even if extraskeletal lesions may be frequently recognized. As a consequence of its rarity, there is no consensus concerning the best standard of care for affected patients. We present the case of a 53-year-old woman with bilateral orbital histologically documented ECD, presenting with an important thickening and swelling of the periorbital tissue and massive involvement of lateral rectal muscles, as documented by magnetic resonance. The patient was successfully addressed to 12 cycles of a weekly lymphoma-designed chemotherapy regimen, including etoposide, mitoxantrone, cyclophosphamide, vincristine, bleomycin, and prednisone (VNCOP-B regimen). Periorbital lesions reduced during the courses of chemotherapy, along with a regression to normal appearance of the extrinsic ocular musculature. This appears as an effective and well-tolerated first-line treatment option for ECD patients, due to the possibility of maintaining an adequate dose intensity, with also a concomitant continuous steroid administration.