Smit and colleagues [1] reported encouraging results with etoposide in one case of the hypereosinophilic syndrome. We report our long-term experience using etoposide to treat two patients with the syndrome.

Patient 1, a 50-year-old man, developed symptoms of the syndrome in 1984, including an elevated absolute eosinophil count (range, 1800 to 8000 cells/mm³); pruritic, erythematous, scaly eruption; cytolytic hepatitis; and eosinophilic infiltration of the pulmonary system, parotid gland, and bone marrow. Prednisolone (1.5 mg/kg of body weight per day) was started in November 1984 with a good initial response but could not be tapered to less than 35 mg/d despite addition of vincristine, cytarabine, and hydroxyurea. In December 1985, intravenous etoposide (300 mg/m² body surface area daily for 2 days) was given, and courses were repeated biweekly for 2 months and then every month thereafter. After the first course, the patient's eosinophil count decreased to less than 500 cells/mm³, and his clinical manifestations were controlled after 5 courses of therapy. After 70 courses of etoposide, prednisolone was tapered to 10 mg daily, and a stable clinical and biological remission was achieved. Etoposide was then withdrawn in March 1993 with no relapse.

Patient 2, a 47-year-old man who had persistent and unexplained hypereosinophilia (range, 8000 to 10 000 cells/mm³) for a year developed pulmonary (chronic cough), cutaneous (purpura), and neurologic (the pyramidal syndrome) symptoms, with eosinophilic infiltration of the bone marrow. Prednisolone treatment was successful, but the development of severe osteoporosis and steroid dependence necessitated the use of successive steroid-sparing drugs (cyclophosphamide, hydroxyurea, or cytarabine) without further clinical benefit. Etoposide was started 2 years after the initial diagnosis (200 mg daily for 7 days out of 10). Six months later, prednisolone could be withdrawn without any relapse. The patient's eosinophil count remained stable at around 2000 cells/mm³. All visceral manifestations of the hypereosinophilic syndrome disappeared with excellent tolerance of the drug after a 7-year follow-up.

In both cases, etoposide rapidly improved both the eosinophil count and visceral manifestations of the disease, reduced the necessity for corticosteroid-sparing drugs, and maintained a good clinical response for 7 years. Etoposide should therefore be considered in the management of the hypereosinophilic syndrome, particularly in patients with inadequate responses or unacceptable side effects from steroids and conventional chemotherapy [2].