Microadenoma (Prolactinoma)

Image and Features

This coronal CT slice was made immediately after intravenous injection of iodinated contrast material. Because the pituitary and infundibulum are outside of the brain, they have no blood brain barrier. Therefore, the contrast material gets into these tissues immediately. Note how much brighter the pituitary and infundibulum are compared to the adjacent brain tissue. Because the contrast material is in the vascular space, the cerebral arteries are also well seen. In contrast, the microadenoma does not have a rich blood supply like the pituitary and therefore shows up as an area of diminished intensity on the left side of the pituitary fossa.

Additional Teaching Points

Most microadenomas are also prolactinomas. Most prolactinomas are about 5 mm in size and are visualized on either contrast enhanced CT or gadolinium enhanced MRI as areas of diminished signal.

Forward to Case 15: Macroadenoma (Prolactinoma)

Back to Case 13: Normal Pituitary Gland

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