Primary Histiocytic Sarcoma, an Extremely Rare Neoplasm: Report of a Case Presenting as a Skin Lesion - Shateri Amiri, Bahareh; Esfandbod, Mohsen; Ghanadan, Alireza; Taslimi, Reza; Kosari, Farid (Reports of Radiotherapy and Oncology, 2020)