Incidental pituitary lesions in 1,000 unselected autopsy specimens.
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.
Teramoto
A
A
Department of Neurosurgery, Toranomon Hospital, Tokyo, Japan.
Hirakawa
K
K
Sanno
N
N
Osamura
Y
Y
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