Langerhans cell histiocytosis: unusual bone marrow infiltration-report of 2 cases in Ecuador.

Langerhans cell histiocytosis (LCH) is a histiocytic neoplasm characterized by the abnormal proliferation of Langerhans cells. Bone marrow (BM) involvement is associated with high-risk disease and poor survival. Although BM involvement is particularly uncommon, no reported cases of LCH with BM infiltration have been documented in Latin America until now.