RESUMO
Nasopharyngeal cancers account for 45% of all ear -nose and throat cancers at the National Institute of Oncology [cancer registry]. Carcinomas are by far the most frequent with the particularity of being tightly linked to the presence of Epstein-barr virus, sensitive to radiation therapy and lymphophilic revealed by cervical masses in 40% of the cases. A precise and reliable anatomo pathological diagnosis is therefore manasatory before intiating any treatment. Methods and The authors report the results of histopathologic techniques [routine and special stains immunohistochemistry] in the diagnosis of 143 biopsies of the rhinopharynx with a frequency of undifferentiated carcinoma of the nasopharynx [UCNT]. All biopsies of suspicion of relapse were inflammatory corresponding to mycotic inflammation in half of the cases. A special emphasis is made on the conclusive contribution of in situ hybridization on paraffin sections in positive and differential diagnosis with regard to the results described in the litterature. Therefore, in the particular context of nasopharynx cancer-frequent in our country, sensitive to radiation therapy but with possible relapses-, the authors emphasise on the specific utility, besides basic and special stainings and immunohistochemistry, of in stiu hybridization of paraffin sections, to search for the presence of Epstein-barr virus particles in tumoral cells. This technique should, indeed, be used as reliable routine technique allowing positive diagnosis of relapses and differential diagnosis in the cases of cervical masses without a known primary site and an extensive cancer of the rhinopharyngeal and sinonasal regions