Successful Treatment of Histiocytic Sarcoma in Childhood.

Histiocytic sarcoma (HS) is a rare malignant neoplasm that belongs to malignant histiocytoses. HS primarily occurs in adult males and is exceptionally uncommon in pediatric populations. Extranodal regions represent the most common sites of HS manifestation. Diagnosis necessitates histopathological evidence of neoplasm, along with verification of cellular origin through specialized studies. Here, we describe a case of a three-year-old female toddler with HS in her calf that was successfully treated with the chemotherapy protocol of Langerhans Cell Histiocytosis (LCH)-IV, the International Collaborative Treatment Protocol for Children and Adolescents with LCH, version 1.3.