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Essentials of Diagnosis
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Clinical and biochemical evaluation for pituitary hormone hypersecretion is negative
MRI shows a pituitary microadenoma (<1 cm diameter) or macroadenoma (≥ 1 cm diameter)
Headache, visual field compromise and anterior hypopituitarism are common with macroadenomas
Elevated serum PRL with macroadenomas may be due to stalk compression
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General Considerations
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Benign neuroendocrine neoplasms that do not produce symptoms from hormone oversecretion
Nonfunctioning pituitary microadenomas (< 1 cm) are common, detected as an incidental finding in 4–37% of brain CT or MR imaging
Account for up to 14–54% of all pituitary adenomas and are more frequent with advancing age
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Nonfunctioning pituitary macroadenomas
Measure 1 cm or larger
Tend to be more aggressive than functioning pituitary adenomas
Frequently present with mass effect symptoms, including
Larger macroadenomas frequently cause some hypopituitarism, particularly hypogonadotropic hypogonadism
Nonfunctioning pituitary microadenomas are asymptomatic
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Differential Diagnosis
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