Treatment of Langerhans cell histiocytosis with subcutaneous cytarabine.

Patients with Langerhans cell histiocytosis (LCH) have been effectively treated with intravenous cytarabine. Intravenous or subcutaneous cytarabine infusions have been effective for leukemia patients, and pharmacokinetic studies have shown very similar blood levels of the drug with either route. We present three LCH patients treated with subcutaneous cytarabine either because intravenous access could not be maintained or due to patient refusal. One patient with pulmonary and skin LCH had a complete response. Another patient had a partial response of pulmonary and cutaneous lesions, but progressive bone disease. The third patient was treated for LCH-related cerebellar changes eight years after the diagnosis of isolated diabetes insipidus, with stable brain MRI for 5 years post-treatment. Subcutaneous cytarabine administration provides an alternative for patients with LCH in whom vascular access is not possible or practical, such as in some resource-limited circumstances.