title: Nasopharyngeal cystic lesions: Tornwaldt and mucous retention cysts of the nasopharynx: findings on MR imaging.
abstract: OBJECTIVE
  Nasopharyngeal cystic lesions are commonly encountered on magnetic resonance imaging with significantly overlapped imaging characteristics. The purpose of this study was to determine the prevalence and distinguishing imaging features of cystic lesions in the nasopharynx in the largest patient series to date.
  
  
  METHODS
  After institutional review board approval, consecutive head magnetic resonance images of 3000 patients performed at 1.5 T between June 2010 and April 2011 were retrospectively reviewed for cystic nasopharyngeal lesions. Location, size, and signal characteristic of cystic lesions were recorded. Electronic medical records were reviewed for patient demographics, symptoms, and underlying conditions.
  
  
  RESULTS
  Among 3000 patients, 6% had Tornwaldt cysts (peak prevalence, 51-60 years old) and 10% had mucous retention cysts (peak prevalence, 41-50 years old). A significant correlation between human immunodeficiency virus infection and mucous retention cysts was observed (P < 0.001).
  
  
  CONCLUSIONS
  The prevalence of Tornwaldt cysts was slightly higher than previously described in the literature. Additionally, younger and older patients had the lowest prevalence of Tornwaldt cyst, suggesting these lesions are acquired and subsequently involute with time. A significant correlation was observed between human immunodeficiency virus infection and mucous retention cysts.
authors.affiliation: From the *Department of Radiology, Boston Medical Center, Boston University School of Medicine, Boston, MA; †Department of Radiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan; and ‡Department of Otolaryngology-Head and Neck Surgery, Boston Medical Center, Boston University School of Medicine, Boston, MA.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Sekiya
authors.forename: Memi
authors.initials: M
authors.lastname: Watanabe
authors.forename: Rohini N
authors.initials: RN
authors.lastname: Nadgir
authors.forename: Karen
authors.initials: K
authors.lastname: Buch
authors.forename: Elisa N
authors.initials: EN
authors.lastname: Flower
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaneda
authors.forename: Osamu
authors.initials: O
authors.lastname: Sakai
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003560:Cysts / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009302:Nasopharyngeal Diseases / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies