title: Surgical, radiologic, and histologic findings of the antrochoanal polyp.
abstract: BACKGROUND
  Of 15 patients with primary unilateral antrochoanal polyps (ACPs), we noticed that all ACPs except one extended through the accessory ostium of the maxillary sinus projected posterior along the nasal cavity. We observed no structural changes in ostiomeatal area on a coronal computed tomography scan.
  
  
  METHODS
  We classified 15 patients with ACP into three stages according to the coronal computed tomography findings of (i) status of the accessory ostium of the maxillary sinus and (ii) level of extension to the nasopharynx. The extent of inflammation in the computed tomography and histologic aspects were also evaluated according to such stages.
  
  
  RESULTS
  In three patients, ACPs did not extend to the nasopharynx (stage I). Among the other ACPs reaching the nasopharynx, complete occlusion of the opening (stage II) was noted in seven patients, and partial occlusion of the opening (stage III) was noted in five patients. The extent of ipsilateral, as well as bilateral, inflammation in the maxillary sinus in stages I and II was greater than that in stage III. More severe inflammatory cell infiltration was observed in stage II in histologic examination.
  
  
  CONCLUSIONS
  We hypothesize that stage I may correspond to an early stage, stage II to full-blown disorder, and stage III to a regression stage. When the exit site of an ACP is the accessory ostium, this opening should be connected to the natural ostium of the maxillary sinus to prevent a possible recirculation phenomenon.
authors.affiliation: Department of ORL-HNS, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Korea.
authors.forename: Seung-Kyu
authors.initials: SK
authors.lastname: Chung
authors.forename: Byung-Chan
authors.initials: BC
authors.lastname: Chang
authors.forename: Hun-Jong
authors.initials: HJ
authors.lastname: Dhong
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008443:Maxillary Sinus / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009298:Nasal Polyps / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D010254:Paranasal Sinus Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D011859:Radiography