Pituitary case example 2

A 45-year old man transfers care to you two months after a 1.75-cm pituitary lesion has been discovered as part of a work-up for intractable headaches (progressively worsening over the past two years.) He has no signs or symptoms of other pituitary dysfunction or visual field disturbances. Past medical history and review of symptoms is negative. He has been on a low dose of a dopamine agonist for the past two months. You perform labs that reveal a normal chemistry panel and CBC, and normal pituitary work-up as described in The Basic Pituitary Disease/Pituitary Tumor Work-up. However, you note that two months ago, the patient's prolactin level was significantly elevated at 75 ng/ml (normal 3-29). This has now normalized after two months of dopamine agonist treatment. The MRI from two months ago reveals a 1.75-cm non-cystic pituitary lesion displacing but not splaying the optic chiasm. 

What Would Your Next Step Be?

  Stay the course. The clinician that started dopamine agonist therapy had excellent instincts. The fact that the prolactin level returned to normal confirms that this is a tumor sensitive to dopamine agonist therapy. The tumor will substantially shrink in the months ahead.

  Schedule this patient to see a neurosurgeon because this pituitary lesion is not a prolactinoma and needs to be removed!

  Be cautious but don t overreact. Since the prolactin level normalized relatively quickly, it would be prudent to re-image the lesion in six months to confirm that it has decreased in size. Surgery would be indicated only if the lesion continues to grow despite dopamine agonist therapy.