Primary renal NUT carcinoma identified by next-generation sequencing: A case report and literature review

Background: NUT carcinoma is a rare aggressive squamous cell carcinoma subtype genetically defined by NUTM1 rearrangements. NUT carcinoma usually has a primitive differentiation state and can be easily misdiagnosed as an undifferentiated carcinoma or Ewing sarcoma. Case presentation We report a case of NUT carcinoma of renal origin initially diagnosed as a malignant small round-cell tumor, likely to be Ewing sarcoma/primitive neuroectodermal tumor. Based on next-generation sequencing (NGS), the diagnosis was revised to NUT carcinoma with a characteristic NUTM1 rearrangement. The patient relapsed after surgery and received a standard NUT carcinoma treatment. However, due to advanced neoplasm progression, first-line chemotherapy failed and the patient died. Conclusion Routine NUT immunohistochemistry staining, NGS, and/or fluorescent in situ hybridization for poorly differentiated carcinoma and sarcoma tumors can help avoid misdiagnosis of NUT carcinoma-related tumors, allowing patients to benefit from bromodomain and extra-terminal motif inhibitor therapy.