Primary cutaneous histiocytic sarcoma: A report of five cases with primary cutaneous involvement and review of the literature

HS must be differentiated from other malignant histiocytoid lesions. Staining for common leukocyte antigen and CD163 are the most reliable markers allowing this distinction. Patients who present with primary involvement of the skin may have a favorable outcome but only if treated relatively early in the course of the disease with complete excision.