Neuroendocrine and squamous cell phenotypes of NUT carcinoma are potential diagnostic pitfalls that discriminating it from mimickers, such as small cell and squamous cell carcinoma.

"Declarations Ethics approval and consent to participateThis study involved human participants but was granted a waiver for the requirement of informed consent due to retrospective analysis of anonymized data. The study was conducted in accordance with the ethical standards of the institutional review board at the JFCR, and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The approval number is [JFCR (#2012–1042)]. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding Kentaro Inamura received Grants-in-Aids for Scientific Research (Kakenhi) (#: 19K07426) from the Japan Society for the Promotion of Science (JSPS). Yuichi Ishikawa received Grants-in-Aids for Scientific Research (Kakenhi) from the Japan Society for the Promotion of Science (JSPS) (grant #: 19H03446), grants from the Japan Agency for Medical Research and Development (AMED), funding for mesothelioma projects entrusted by the Ministry of Environment, and is a consultant for Fujirebio Inc."