New techniques and tumor nomenclature

New techniques in pathology can effect tumor nomenclature by leading to new concepts which may then give rise to new terms. Pathologists generate morphological data. They are obliged to provide consistent data for those who depend on standardized terms, eg, clinical trials, tumor registries and practising physicians and surgeons. They face the dilemma of when to replace a standard term with a new term. The following are recent examples of situations in which new techniques have had an impact on tumor nomenclature but which have raised questions about the applicability of new terms in routine diagnostic reports: --tumors of the lung, particularly when studied by electron microscopy: should the ultrastructural heterogeneity of lung tumor types be expressed or ignored in routine diagnosis? --the APUD and neuroendocrine carcinoma concepts: is there a need to rename carcinoids and small cell carcinomas? --endocrine elements in carcinomas: are the following terms useful for diagnosis: amphicrine carcinoma, argentaffin cell carcinoma, biphenotypic carcinoma? The recognition that conceptual terms and descriptive terms have separate functions may help pathologists deal with terminological change.