Prevalence of NUT carcinoma in head and neck: Analysis of 362 cases with literature review

Background Nuclear protein in testis (NUT) carcinoma is a poorly differentiated carcinoma defined by the presence of NUT gene rearrangement. In the head and neck, the true prevalence of NUT carcinoma is unknown. Methods We retrospectively investigated NUT expression with clinicopathologic features in 362 patients of poorly differentiated or undifferentiated carcinomas in the head and neck, and reviewed the literature reports. Results Four (4/362, 1.1%) cases showed strong nuclear expression for NUT‐specific monoclonal antibody, and all these tumors were in the sinonasal tract (4/40, 10%). The clinical outcome and histology were diverse unlike previously described. Although previous studies reported different frequency results according to study subjects, frequencies in sinonasal tract are relatively constant (10/80, 12.5%). Conclusions This is the largest study on the prevalence of NUT carcinoma in head and neck areas. It is important to include in the differential diagnosis of poorly differentiated carcinoma, particularly in the sinonasal tract.