primary nasopharyngeal adenocarcinomas ( npacs ) are extremely rare malignant tumors accounting for 0.38% to 0.48% of all malignant nasopharyngeal neoplasms and 0.70% of all nasopharyngeal carcinomas .
these properties mean that the treatment of choice for these tumours is total surgical resection of the primary tumor , and this has an excellent prognosis .
traditionally , because of the anatomic complexity of the nasopharynx , resection of nasopharyngeal tumors has used an external approach . however , here we suggest that an alternative exclusively endoscopic surgical strategy should be considered .
this is because this tumor type is pedunculated , histologically relatively non - aggressive and , further , we have now refined our existing published endoscopic technique and successfully used it to resect different types of tumour [ 2 - 9 ] .
here we describe our exclusively endoscopic approach for the resection of primary nasopharyngeal adenocarcinoma . to the best of our knowledge ,
this is the first time to excise the nasopharyngeal adenocarcinoma via the strictly endoscopic approach .
the first case is a 28-year - old female with the symptoms of nasal bleeding for about 3 weeks .
was noted by nasopharyngoscopic exam and biopsy with magnetic resonance imaging ( mri ) was performed .
mri showed an approximate 1.5 cm pedunculated nodule attaching on the left lateral wall ( fig .
1 ) . the second case is a 58-year - old male with the symptoms of blood tinged sputum for about 1 month .
mri showed an approximate 2.2 cm pedunculated nodule occupying the nasopharyngeal airway , from the nasopharyngeal roof .
the pathologic biopsy report of both patients showed low - grade papillary adenocarcinoma composed of papillary fronds lined by pseudostratified columnar cells with bland unclei . according to the preoperative pathologic biopsy
the operations were performed under general anesthesia with our patient placed in a semi - sitting position .
prior to surgery , the nasal turbinates were decongested using cotton packs saturated with 1:100,000 bosmin for 15 minutes .
the posterior half of the nasal septum , vomer , and inferior turbinate of the lesion site were excised to create a working space for the endoscope and to expose the tunour .
endoscope versatility has improved considerably in recent years , and by using a 4 mm diameter , 0 degree , 30 degree , and 70 degree angle endoscope ( karl - storz , tuttlingen , germany ) , it was possible to remove the exposed tumor completely leaving an adequate mucosal surgical margin .
the lateral wall of the nasal cavity ( including part of the eustachian tube ) , the roof ( deep to the periosteum of skull base ) , and the posterior wall ( deep to prevertebral fascia ) were totally resected by a continued - wave , contact type of diomed 25 diode laser ( diomed co. , cambridge , uk ) .
frozen sections prepared from the surgical margin tissue were assessed during the nasopharyngectomy to assess whether all the tumor had been removed .
the wound surface was covered with a free mucosal flap harvested from the inferior nasal turbinate and held in place by absorbable gelform .
the nasal cavity was packed with nasal packing and a balloon - inflated foley catheter for 72 hours after the operation .
the 2 operations were performed successfully and all surgical resection margins were free of tumor .
total operation times were 100 and 90 minutes respectively , and the patients were discharged from hospital only 4 to 5 days after surgery . as the resection margins were clear there was no need to perform postoperative radiotherapy or chemotherapy .
one of the patients ' mri pre- and postsurgery is shown in fig . 1 .
low - grade papillary adenocarcinoma is one histologic pattern of the polymorphous low - grade adenocarcinoma . with a very low tendency for aggressive behaviour of this carcinoma ,
the recommended treatment of low - grade papillary adenocarcinomas is currently surgical excision , and the results are excellent .
lymphatic spread been not been described in any case , so neck dissection is not normally necessary unless there is clinical evidence that suggests lymph node involvement has occurred . if it has not been possible to surgically resect all the tumor then adjuvant radiotherapy should be carried out to prevent tumor recurrence . in this study ,
the 2 tumors were excised radically with adequate margins , thus the postoperative radiotherapy was not performed .
nasopharynx anatomical structure is extremely complex and so existing surgical techniques use a variety of open procedures including facial translocation , midfacial degloving , maxillary swing , lateral rhinotomy , or a transpalatal approach .
the surgical approach that is used depends upon both the tumor extension and the surgeon 's experience and preference . in 2007 , we have reported the minimally invasive endoscopic nasopharyngectomy in the treatment of recurrent t1 - 2a nasopharyngeal carcinoma . because of the pedunculated shape of nasopharyngeal adenocarcinomas , the relatively benign histological features of this type of tumour and also given the recent improvements in endoscopic technique and instruments [ 2 - 9 ] , we think the exclusively endoscopic approach is feasible for selected nasopharyngeal adenocarcinoma .
however , it is not the intent of this report to suggest that the exclusively endoscopic approach is superior to the conventional open approaches .
instead , the goal of this study is to highlight the experience with the minimally invasive endoscopic approach at the early juncture . with respect to the anatomic limitations of exclusively endoscopic excision of nasopharyngeal adenocarcinoma
, these would include tumor invasion to the central skull base bone superiorly , the pharyngobasilar fascia laterally , the prevertebral fascia posteriorly , and oropharynx inferiorly .
if the extent of the tumor is found to be far beyond the nasopharynx during operation , we believe endosopic nasopharyngectomy can be changed to conventional open surgery without difficulty .
first , primary nasopharyngeal adenocarcinomas are extremely rare ; we can not analyze the quality of life between our 2 cases and similar cases operated with a conventional open procedure .
second , to gain a conclusive result , we need a larger series of patients with longer follow - up .
however , the early results appear encouraging . not only for the early recurrent nasopharyngeal carcinoma
we find that the procedure is curative , cuts down the length of the operation , decreases wound - related complications , shortens hospital stay , and moreover gives a better cosmetic outcome .
 we reported two patients with nasopharyngeal adenocarcinoma resected by using the exclusively endoscopic approach . 
 case reports and a review of the world literature concerning nasopharyngeal adenocarcinoma . 
 the tumors were resected successfully via the exclusively endoscopic approach and no conversions to the conventional approach were necessary . 
 the two patients were followed up for 26 and 18 months respectively , and no recurrence was noted without postoperative chemotherapy or radiotherapy . to the best of our knowledge , 
 this is the first report of endoscopic resection of nasopharyngeal adenocarcinoma . 
 our experience revealed that not only for the early recurrent nasopharyngeal carcinoma , the exclusively endoscopic nasopharyngectomy can be expanded for the resection of selected nasopharyngeal adenocarcinoma . 
INTRODUCTION
CASES REPORT
RESULTS
DISCUSSION