title: Imaging characteristics of dacryocystocele diagnosed after surgery for sinonasal cancer.
abstract: OBJECTIVE
  A dacryocystocele forms when tears accumulate within the lacrimal sac as a result of an obstruction more distally in the lacrimal drainage apparatus, which may occur as a complication of sinonasal surgery. The purpose of this study was to define the imaging characteristics of a postoperative dacryocystocele occurring after surgery for sinonasal cancer and to review the anatomy of the nasolacrimal drainage apparatus.
  
  
  METHODS
  We reviewed the clinical records and imaging findings of 8 patients who underwent surgery for sinonasal cancer and were diagnosed with a postoperative dacryocystocele between August 2001 and November 2005. The imaging studies performed at the time of diagnosis of dacryocystocele were CT in 6 patients and MR imaging in 2 patients.
  
  
  RESULTS
  On both CT and MR imaging, dacryocystoceles had a characteristic appearance of a fluid collection with thin rim enhancement along the course of the affected nasolacrimal duct, with no adjacent solid components. In none of the patients was the dacryocystocele confused with a recurrent tumor.
  
  
  CONCLUSIONS
  Dacryocystocele after surgery for sinonasal cancer has a characteristic appearance on CT and MR imaging. Familiarity with this complication of sinonasal surgery and its appearance on imaging will enable radiologists to avoid misinterpreting dacryocystocele as a recurrent tumor or another process.
authors.affiliation: Department of Radiology, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA. matthew.debnam@mdanderson.org
authors.forename: J M
authors.initials: JM
authors.lastname: Debnam
authors.forename: B
authors.initials: B
authors.lastname: Esmaeli
authors.forename: L E
authors.initials: LE
authors.lastname: Ginsberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006547:Hernia; D006801:Humans; D007766:Lacrimal Apparatus Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000000981:diagnostic imaging / Q000473:pathology; D010255:Paranasal Sinus Neoplasms / Q000601:surgery*; D011183:Postoperative Complications; D014057:Tomography, X-Ray Computed