Abstract
Langerhans Cell Sarcoma (LCS) is an extremely rare and aggressive neoplasm with limited consensus on optimal treatment. We report the case of a 56-year-old woman with refractory Langerhans Cell Histiocytosis (LCH) that transformed into Langerhans Cell Sarcoma (LCS) who achieved complete remission following chemotherapy with cladribine, high-dose cytarabine, G-CSF, and mitoxantrone (CLAG-M), and subsequent allogeneic hematopoietic stem cell transplantation (HSCT). This case highlights the potential role of allogeneic HSCT as an effective therapeutic option for refractory LCS and underscores the importance of reporting additional cases to guide future management strategies in this rare malignancy.