A rare case of adolescent Histiocytic Sarcoma

Histiocytic sarcoma is a rare haematopoietic malignancy with an aggressive nature and poor prognosis. It occurs infrequently in children and adolescents, with only a few cases reported worldwide.A well 14-year-old male patient presented with a slow-growing mass on his right lateral malleolus. Imaging suggested a benign tumour and an excision biopsy was performed. Morphological examination raised suspicion for a histiocytic neoplasm, which was confirmed by immunohistochemistry (CD68 and CD45 positive, CD1a, CD30 and ALK1 negative). Because of the tumour’s rarity, it was sent for an international confirmatory pathological review.Contribution: Our patient underwent a wide local resection followed by radiotherapy (50 Gy). No adjuvant chemotherapy was prescribed, and he has remained in remission 2 years following his diagnosis.