Abstract
BACKGROUND: Various therapeutic options are available for the management of Langerhans cell histiocytosis. However, treatment administered to control this disease may be complicated by acute leukemia. CASE PRESENTATION: A 34 years old male was diagnosed to have Langerhans cell histiocytosis in March 1999. Unfortunately, the cytotoxic chemotherapy and radiotherapy given to control the repeated relapses and exacerbations of the primary disease predisposed him to therapy-induced myelodysplastic syndrome which transformed into acute myeloid leukemia. After achieving complete remission of his leukemia, the patient received an allogeneic hematopoietic stem cell transplant. The allograft was complicated by chronic graft versus host disease that was controlled by various immunosuppressive agents and extracorporal photophoresis. CONCLUSION: Management of complicated cases of histiocytosis requires various therapeutic modalities and a multidisciplinary approach. Having complications of therapy eg myelodysplasia or acute leukemia make the outcome more dismal and the management options limited to aggressive forms of treatment. High dose chemotherapy followed by an allograft may be a curative option not only for therapy-related myelodysplasia/acute leukemia, but also for frequently relapsing and poorly controlled Langerhans cell histiocytosis.