Selected Correspondence of

The diagnosis of thymic epithelial neoplasm has been a topic of controversy for many years. Reasons for this include the lack of predictive value associated with the morphology of these tumors and the multiplicity of classification schemes and terminologies proposed over the years. Recently, a new classification schema was introduced by the World Health Organization (WHO) in an attempt to standardize nomenclature and facilitate the diagnosis of primary thymic epithelial neoplasms. This schema, although not originally intended as a new histologic classification but rather as a means for translating equivalent terms from the various existing classifications, has represented a major step forward in the field. However, problems still exist with the WHO schema, particularly with some of the criteria for the various histologic subtypes as well as with issues of inter-observer reproducibility. For this reason, we favor utilizing a much more simplified approach to the morphologic classification of thymic epithelial neoplasms. Herein I will detail my personal approach to the morphologic diagnosis of thymoma, with a brief explanation for the rationale for simplifying the existing diagnostic categories