The descriptions of the tumors arising in the nose and in the accessory sinuses give rise to considerable confusion and do not appear to be adequately understood either from the clinical or from the pathologic viewpoints. The textbooks have little to say concerning these lesions and the nomenclature is especially confusing. This is particularly true concerning that type of vascular tumor variously described as angioma, angiosarcoma, and hemangio-endothelio fibroblastoma. The reasons for these innumerable diagnoses of the blood vessel neoplasms in the nasal mucous membrane apparently are: the rarity of the condition, the fact that the tissues obtained for histologic examination are very scanty in amount or are traumatized in removal, or the fact that the histologic picture may be altered by previous radium therapy and infection. PATHOLOGY Hemangio-endotheliomas of the nasal mucous membrane are designated by many names. Some of the tumors that have been described as angioma, angiosarcoma,