Expression of P16 in NUT carcinomas with no association with human papillomavirus (HPV).

NUT carcinoma (NC) is a rare malignant neoplasm usually located in the midline, including the upper aerodigestive tract. NC is an aggressive and highly lethal type of carcinoma. It is defined by the rearrangement of the nuclear protein in the testis (NUT) gene on chromosome 15q14. In most cases, the NUT is involved in a balanced translocation with the BRD4 gene on chromosome 19p13.1, an event that creates a BRD4-NUT fusion gene. The relationship between the human papillomavirus (HPV), p16, and upper aerodigestive tract cancer has been long postulated. In this study, we evaluated the relationship of the p16 expression in 4 cases of NCs and its eventual association with HPV. All 4 cases presented typical histopathologic findings with nuclear positivity of the NUT protein and strong expression for p16. None of these cases, however, showed an association with HPV evaluated by polymerase chain reaction. Despite the expression of p16, this negative result for HPV indicates that HPV infection probably does not play a role in the pathogenesis of NC.