Saturday, January 23, 2010

January 22nd - MHH - All about the Pituitary

Today at Morning Report a case of a piuitary mass in a patient with history of treated prolactinoma was presented.  Here is an overview of pituitary masses, pituitary disorders, and more on prolactinomas

Pituitary Mass:

Clinical Symptoms: Pituitary masses cause one of two major categories of symptoms - those of mass effect and those of either hypersecretion or hyposecretion of hormones.  Mass Effect from tumor growth can cause headache, seizures, diploplia, blurry vision and/or visual deficits.

When you see a pituitary mass, you should order the following:
TSH and FT4
Alpha Subunit (marker produced by GH) and IGF-1
Estradiol in Females
Testosterone in Men

Specific Symptoms: Will depend on hormone effects, some of which include:
Patients can get S/Sx of hyper/hypothyroidism
Patients may get cushing's disease or adrenal insufficiency (the former is more common)
Acromegaly may result as well
Prolactinoma symptoms (more below)

Treatment: Depends on treating the causes of hormone excess or deficiency.  Surgery is usually used in these cases as well. 


Classified as microadenomas (<1cm) or macroadenomas (>1cm).  Usually macroadenomas cause visual field defects, but microadenomas are more common overall

Symptoms:  In Men - Loss of libido, impotence, loss of peripheral body hairDiagnosis: Imaging (MRI) and Prolactin Levels. You should work these patients up for "pituitary masses" as stated above - importantly obtaining a TSH (to rule out secondary elevated PRL caused by an elevated TRH level OR concurrent hypothyroidism) and cortisol levels, in addition to other hormones. 

                      In Women - Amenorrhea, galactorrhea and hirsutism
                      If the tumor is large enough, compression of nearby cells can lead to deficiency  
                                of other hormones - commonly TSH, GH and ACTH.                   
                      And of course, mass effect symptoms depending on size of tumor

So, in morning report there was some discussion was raised about levels of Prolactin. What is normal? How high of a levels leads you to suspect prolactinoma? What else raises levels of PRL?

Normal:  <25ng in females, <20ng in Males and Children
40-85 ng: Craniophayngomas, Hypothyroidism and Drugs (esp anti-emetics, antipsychotics and TCAs
~50ng: 25% chance of pituitary tumor and ~100ng: 50% chance of pituitary tumor
>150ng: Usually a prolactinoma, and if the level is >200 it is about 100% chance of being a prolactinoma

Other causes of increased prolactin include:
Any pituitary lesion
Hypothalamic Lesions (histiocytosis X, sarcoid, TB, glioma)
Endocrine: Hypothyroidism, Addison's Disease, Glucortocoid Excess, COS
Ectopic production: Bronchogenic carcinoma, RCC
Neurogenic: Post-Seizure, Spinal Cord Lesion, Nursing
Stress (includes vigorous exercise and post-op)
Chronic Kidney Disease
Drugs (antiemetics, antipsychotics, opiates)

Treatment of Prolactinoma:Medical treatment with dopamine agonists - bromocriptine and cabergoline.  Bromocriptine is not well tolerated due to side effects, including orthostasis, nausea and dizziness. Bromocriptine, however, is the choice of treatment in pregnant patients.  Nonetheless, both medications can both reduce tumor size and prolactin levels. Pergolide was previously used, but withdrawn due to it's association with valvular disease in patients. 

Surgical treatment is done if drug therapy does not help or is poorly tolerated.  Still, drugs are usually given post-operatively.   

Irradiation is given usually only if the lesion is very large or medical/surgical therapy doesn't help much

Other Pituitary Disorders:

Empty Sella Syndrome - This occurs when the CSF compresses the pituitary.  Mostly present in a multiparous women. Can be secondary to irradation or trauma.  Sometimes this  is benign and does not require treatment, other times hormone replacement is needed. 

Pituitary Apoplexy - Infarct and hemorrhage into the pituitary.  Patients will present acutely with signs of meningiitis (i.e. meningismus and headache) as well as nausea/vomiting, altered mental status, visual changes and vertigo.  If you suspect this, order imaging (MRI is better than CT) and if it is present, neurosurgery needs to be called ASAP!  Sometimes steroids are used for minor cases, but patients with severe symptoms need surgical decompression.

Sheehan Syndrome - Postpartum infarct of pituitary with usual decreases in almost all hormones - TSH, ACTH, GH, LH, FSH as well as sometimes causing DI.  Hormone replacement is the treatment of choice. 

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