[Nomenclature-inherent problems in oncology exemplified with primary thymogenic tumors].

Controversy about thymic organogenesis and its complex ontogenesis and functions, have led to several contradictory classifications of primary thymic tumors. Apart from the mesenchymal tumors such as thymolipomas there are four cell types which may represent the cellular origins of primary neoplastic lesions of the thymus: Thymocytes (T-lymphoblastic lymphoma), thymic B-lymphocytes (thymic lymphoma of the B-cell type), epithelial cells (thymomas, thymic carcinomas), and neuroendocrine cells (carcinoid tumors of the thymus).