Incidental pituitary lesions in 1,000 unselected autopsy specimens

Radiology. 1994 Oct;193(1):161-4. doi: 10.1148/radiology.193.1.8090885.


Purpose: 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.

Materials and 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.

Conclusion: Incidental lesions should be considered a cause of false-positive findings (6.1%) when an imaging diagnosis is made of a functioning pituitary microadenoma.

MeSH terms

  • Adenoma / diagnosis
  • Adenoma / epidemiology*
  • Adenoma / pathology
  • Adolescent
  • Adult
  • Aged
  • Child
  • Craniopharyngioma / epidemiology*
  • Craniopharyngioma / pathology
  • False Positive Reactions
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Pituitary Gland / pathology*
  • Pituitary Neoplasms / diagnosis
  • Pituitary Neoplasms / epidemiology*
  • Pituitary Neoplasms / pathology
  • Tomography, X-Ray Computed