Large Cell Carcinoma

Originally large cell carcinoma was defined by the absence of visible glandular or squamoid features. Due to immunohistochemistry introduced into NSCLC diagnosis, this exclusion was extended. Solid carcinomas negative for either TTF1 or p40 without visible glandular or squamoid differentiation are now large cell carcinomas. In addition, as this requires whole tumor sections, this is restricted to resection specimen. The former variants are now splitted: LCNEC into the neuroendocrine carcinomas, lymphoepithelioma-like carcinoma into a separate entity, and rhabdoid carcinomas are now no longer regarded as a separate entity, but instead rhabdoid features should be reported. Clear cell changes are seen in different carcinoma types and are therefore also reported but do not comprise an entity.