Juvenile Nasopharyngeal Angiofibroma: The Routes Of Invasion And Risk Factors Of Recurrence

PartⅠJuvenile Nasopharyngeal Angiofibroma:the Routes of InvasionObjectiveJuvenile nasopharyngeal angiofibroma (JNA) is a locally invasive, vasoformative neoplasm occurring almost exclusively in adolescent males which presents rarely. Our aim is to analysis specific characteristic of the tumor's invasion pattern and study the three-dimensional reconstruction.MethodsOur study was based on a study of the imaging (enhanced CT scan) and three-dimensional reconstruction of male patients with histologically proven angiofibroma; a series collected over 6 years since 2004 in Fudan university affiliated eye, ear, nose and throat hospital.Eighty cases with histological diagnosis of JNA were studied, including 46 untreated patients and 34 recurrent cases. The extension of the tumor was evaluated with enhanced CT scans (iodine-contrasted coronal and/or axial 6mm cuts). The route of invasion of each craniofacial site was deduced by the dislocation and/or erosion of the bony wall.From the pterygoid canal, the anatomical sites were classified according to the direction of growth:anterior (nasal cavity and maxillary sinus); posterior (nasopharynx and pterygoid process); superior (sphenoid sinus, cranial fossa and orbitary cavity) and lateral (pterygopalatine fossa and infratemporal fossa). And study the distribution of rumor stage (Radkowski,1996).Seventeen iodine-contrasted images (0.75-1.00mm cuts) were obtained and then sent to the Mimics 13.0 software to make three-dimensional reconstruction images. The reconstruction images can be observed from any directions and any level on the computer. The tumor, the bones of skull and the blood vessel can be studied as a whole or as individual.ResultsThe main sites of invasion:The pterygoid canal and sphenopalatine foramen region were affected in all untreated cases. Then followed locations in proper order are posterior nasal aperture, nasal cavity, pterygopalatine fossa, nasopharynx, sphenoid sinus, pterygoid process, ethmoid sinus, maxillary sinus, infratemporal fossa, orbital apex and skull base.The distribution of JNA stages:In the 44 untreated patients, the main stages areⅡA (17.39%) andⅡC(43.48%).Ⅰstage counted 6.52%;Ⅱstage counted 69.57% andⅢstage counted 23.91%.The routes of invasion:The pterygoid canal and sphenopalatine foramen region were affected in all untreated cases. According to the growth pattern of JNA, pterygoid canal may be the origin site of JNA. JNA occurred at the front of pterygoid canal accounted for 58.14%; occurred at the post of the pterygoid canal accounted for 41.86%. From pterygoid canal JNA can invade sphenopalatine foramen, sphenoid sinus and pterygopalatine fossa directly. And then invade adjacent structures through these three locations. JNA can invade ethmoid sinus and skull base through sphenoid sinus; invade nasal cavity, posterior nasal aperture and nasopharynx through sphenopalatine foramen; invade sphenopalatine foramen, pterygoid process, maxillary sinus, orbital apex and infratemporal fossa through pterygopalatine fossa. There are 44.19% of the cases which invaded the medial pterygoid plate to pterygoid fossa. The growth directions of JNA:There is no significant difference between the four directions.Five sites were invaded by more than one route:1) JNA can invade sphenopalatine foramen region through pterygoid canal directly or by tumor expansion in pterygopalatine fossa;2) JNA can invade maxillary sinus by tumor expansion in nasal cavity or pterygopalatine fossa;3) JNA can invade sphenoid sinus through pterygoid canal directly or by tumor expansion in aperture of sphenoidal sinus; 4) JNA can invade maxillary sinus by tumor expansion in nasal cavity or pterygopalatine fossa;5) JNA can invade skull base by tumor expansion in sphenoid sinus or orbital apex.Conclusion:1. The main sites of invasion are pterygoid canal, sphenopalatine foramen region, posterior nasal aperture, nasal cavity, pterygopalatine fossa, nasopharynx, sphenoid sinus, pterygoid process, ethmoid sinus, maxillary sinus, infratemporal fossa, orbital apex and skull base.2. In untreated patients, the main stage of tumor isⅡA andⅡC. Pterygoid canal may be the origin site of JNA, about 60% of which occurred at the front of pterygoid canal and another 40% occurred at the post of pterygoid canal. From this point, JNA can invade sphenopalatine foramen, sphenoid sinus and pterygopalatine fossa directly. And then invade adjacent structures through these three locations. There was 44.19% of the cases invaded pterygoid fossa by tumor expansion in medial pterygoid plate.3. There is no significant difference between the four directions.4. Sphenopalatine foramen region, maxillary sinus, sphenoid sinus, maxillary sinus, and skull base were invaded by more than one route.PartⅡJuvenile Nasopharyngeal Angiofibroma:the Risk Factors of RecurrenceObjective Surgical outcomes and prognostic factors were analyzed to determine what factors increased the probability of juvenile nasopharyngeal angiofibroma (JNA) recurrence. And the common sites of its recurrence were studied.Method Our study is based on cases of 130 male patients with historically proven angiofibroma who were surgically treated at Fudan university affiliated eye, ear, nose and throat hospital from 1997 to 2009. The follow-up period ranged from 6 months to 158 months.All clinic data was obtained from patients medical records, including age, embolization preoperatively, stage of tumor, approach of operation and the blood loss. 34 cases of recurrent patient's CT imaging (from2004 to 2010) were obtained and the common sites of recurrence were analyzed.These correlations were statistically analyzed by SAS 1.9 software using Stepwise regression analysis. All P valued<0.05 were considered significant.ResultThe total recurrence rate:There are 36 cases of recurrence in 130 patients and the total recurrence rate is 27.69%.Age and recurrence:The recurrent rate of group whose age<18 is 32.91% and the recurrent rate of group whose age≥18 is 19.61%. The result was statistically insignificant (P= 0.2194).Embolization and recurrence:The recurrent rate of group who had embolization preoperatively is 27.84% and the recurrent rate of group who had not embolization preoperatively is 27.27%. The result was statistically insignificant (P= 0.6033).Stage of tumor and recurrence:The recurrent rate of group ofⅠstage is 9.38%; the recurrent rate of group ofⅡstage is 25.71%; the recurrent rate of group ofⅢstage is 53.57%. The result was statistically significant (P= 0.0001).Approach of operation and recurrence:The recurrent rate of group who had endoscopic surgery is 24.24% and the recurrent rate of group who had traditional surgery is 28.87%. The result was statistically insignificant (P= 0.4714).Blood loss and recurrence:The recurrent rate of group whose blood loss is<800ml is 7.69% and the recurrent rate of group whose blood loss is≥800ml is 36.26%. The result was statistically significant (P= 0.0002).Common sites of recurrence:The recurrent cites in proper order are pterygoid canal, sphenopalatine foramen region, sphenoid sinus, sphenoid sinus, pterygopalatine fossa, pterygoid process, infratemporal fossa, nasal cavity, skull base, ethmoid sinus, maxillary sinus, and orbital apex.The distribution of recurrent JNA stages:In the 34 recurrent cases, the main stages are ⅡB (5.88%),ⅡC(29.41%),ⅢA (14.71%) andⅢB (41.18%)Conclusion1. In this study the total recurrence rate is 27.69%.2. The significant predictors of recurrence in our study were Radkowski classification and blood loss.3. The common recurrent cites are pterygoid canal, sphenopalatine foramen region, sphenoid sinus, sphenoid sinus, pterygopalatine fossa, pterygoid process, infratemporal fossa. And in recurrent cases, the main stages are stages aboveⅡB.