Epstein-Barr virus RNA detection and glandular differentiation in nasopharyngeal carcinoma - Report of 2 cases

Most tumors arising in the nasopharynx are either squamous cell carcinoma o r so-called undifferentiated carcinoma of the nasopharyngeal type. Primary adenocarcinomas of the nasopharynx are rare, and glandular differentiation in undifferentiated carcinoma of the nasopharyngeal type has not been repor ted to date. We report 2 cases of undifferentiated carcinoma of the nasopha ryngeal type that show distinct glandular differentiation by light microsco py, histochemistry, immunohistochemistry, and ultrastructure. Both tumors s howed equal positivity for Epstein-Barr virus latent membrane protein and i n situ hybridization for Epstein-Barr virus genome in the undifferentiated areas of the tumor and those featuring glandular differentiation.