Undifferentiated carcinoma of the nose and paranasal sinuses. An immunohistochemical and clinical study.

Among twenty-six "undifferentiated" tumors of the nasal cavity and paranasal sinuses treated from 1970 to 1990 at the Institute of Otolaryngology of Florence University, 13 were ultimately diagnosed as true undifferentiated sinusonasal carcinoma (SNUC) by conventional light microscopy and use of monoclonal antibodies to epithelial membrane antigen and cytokeratins. SNUC patients, who ranged in age from 20 to 82 years, often had multiple sinonasal symptoms due to very large tumors (nine of 13 tumors were staged as T3-T4) with short average delay of 4 months between onset of symptoms and diagnosis. Both data suggest the high growth capacity and aggressiveness of such a tumor. In our series, follow-up evidenced an overall crude 5-year survival rate of 15.5%. Worse prognostic factors are neck metastases and orbital invasion, according to the behavior of more common carcinomas of the nose and paranasal sinuses. We also found a better prognosis for SNUC primarily arisen in the nasal cavity than in paranasal sinuses (crude 5-year survival rate of 66% vs. 10%, respectively). The histopathological and clinical analysis of our series shows that SNUC is a highly aggressive, uncommon tumor of the nose paranasal sinuses, which should be recognized in advance for a more aggressive treatment by combined multiple therapy.