Juvenile nasopharyngeal angiofibroma: the routes of invasion.

The juvenile nasopharyngeal angiofibroma has a characteristic growth in all directions from its origin. However, the extensions of the tumor seem to be independent, each one with distinct behavior. The aim of this study is to analyze the preferential direction and routes of JNA growth, as well as its correlation with the patient's age. We analyzed 33 patients without any previous treatment, attempting to the extension and routes of tumor's growth (CT scan), and its correlation with the patient's age. The sphenopalatine foramen region was affected in all cases. From this point, a growth towards several routes with a different rhythm was noted, determining variable configurations to the tumor. The lateral and superior growths were the most frequent. The expansion into the pterygopalatine fossa was very frequent and could involve important anatomical structures, determining higher morbidity. Three sites were invaded through more than one route: pterygoid fossa, middle cranial fossa and maxillary sinus. There was no significant correlation between invasion route and patient's age. However, considering the age, there was a concomitance between tumor development and facial growth by "displacement". We discuss this condition, suggesting an explanation to the tumor invasion and expansion inside the pterygopalatine fossa.