title: Incidental pituitary lesions in 1,000 unselected autopsy specimens.
abstract: OBJECTIVE
  To elucidate the frequency of false-positive results in imaging diagnoses of a functioning pituitary microadenoma, the authors studied various kinds of incidental lesions greater than 2 mm in diameter from a larger series of pituitary glands.
  
  
  METHODS
  One thousand pituitary glands were studied in a nonselected autopsy series. Most causes of death were acute diseases or accidents. Each gland was fixed in 10% formalin and was then cut horizontally into three or four pieces, which were prepared for usual light microscopy.
  
  
  RESULTS
  Of 178 glands found to have incidental lesions, 61 (34%) lesions were larger than 2 mm. Included were adenomas and hyperplasias (n = 20), Rathke cysts (n = 37), infarctions (n = 2), and hemorrhages (n = 2). Seventeen (74%) of 23 laterally localized lesions were adenomas, and 33 (87%) of 38 medially situated lesions were Rathke cleft cysts. These lesions were found in 5.8%-8.3% of subjects in every generation aged 30 years or older.
  
  
  CONCLUSIONS
  Incidental lesions should be considered a cause of false-positive findings (6.1%) when an imaging diagnosis is made of a functioning pituitary microadenoma.
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Teramoto
authors.forename: K
authors.initials: K
authors.lastname: Hirakawa
authors.forename: N
authors.initials: N
authors.lastname: Sanno
authors.forename: Y
authors.initials: Y
authors.lastname: Osamura
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003397:Craniopharyngioma / Q000453:epidemiology* / Q000473:pathology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D014057:Tomography, X-Ray Computed