SG 13.3: Cases of Pituitary Disorders Flashcards
A 24-year-old woman who wants to become pregnant has had no menses since she discontinued the use of an oral contraceptive one year ago, and recently, noticed her breast have been leaking milk.
Denies headaches or visual loss, denies dyspareunia, and recently noticed decreased libido.
She had been feeling nauseous.
what’s the most likely cause of her symptoms?
pituitary adenoma, pregnancy, hyperthyroidism, acromegaly, or primary ovarian insufficiency
pituitary adenoma
can’t get pregnant, no period for over a year and galactorrhea so you need to rule out pregnancy but in this case the most likely cause is pituitary adenoma, specifically prolactinoma which is one of the most common pituitary adenomas!
check her medications though to make sure she’s not taking any antipsychotics that could be lowering dopamine levels
which medication can cause hyperprolactinemia?
resperidone, haloperidol, verapamil and metoclopramide
most antipsychotics and any drug that lows dopamine can cause hyperprolactinemia
what’s the next best step if you think a patient has a prolactinoma?
pituitary MRI, IGF-1, serum or urine hCG, or pituitary surgery
what other tests would you order after that?
serum or urine hCG to exclude pregnancy
before you do imaging, exclude any other causes of elevated prolactin or amenorrhea
then after you confirm she isn’t you’d do a pituitary MRI
then order thyroid function test to make sure she doesn’t have hypothyroidism, hepatic/renal function to see if clearance is being effected – if all of this is normal and she’s not on any medications and she has elevated prolactin, then you would get an MRI to confirm
which structures would most likely be jeopardized if a pituitary adenoma continues to increase in size?
optic chiasm
visual disturbances; bitemporal hemianopsia specifically
what is the most appropriate treatment for a prolactinoma?
surgery, radiotherapy, cabergoline or observation
medical therapy aka cabergoline or another dopamine agonist because 90% have a decrease in tumor size
if it fails or the mass is huge and doesn’t decrease in size enough then you can do surgery
radiotherapy is used if there’s no response in medical therapy
A 24-year-old woman who wants to become pregnant has had no menses since she discontinued the use of an oral contraceptive one year ago, and recently, noticed her breast have been leaking milk.
Denies headaches or visual loss, denies dyspareunia, and recently noticed decreased libido.
She had been feeling nauseous.
Prolactin 170 ng/mL (4-30 ng/mL)
TSH 40 mU/L ( 0.4-5 mU/L)
FT4 0.5 ng/dL (0.8-1.8 ng/dL)
MRI shows pituitary enlargement
what is the most appropriate next step in management?
thyroid function test!
dont start a dopamine agonist yet because you haven’t eliminated other causes of hyperprolactinemia
hypothyroidism can be causing elevated prolactin because elevated TRH/TSH can cause hyperprolactinemai
so first treat hypothyroidism then check prolactin again
A 35-year-old woman presents complaining fatigue. She has also experienced frontal headache several days a week over the past year. She says that she tires easily and sweats with minimal activity.
She has had chronic pain and stiffness in the knees, shoulders, and hands, as well as occasional numbness and tingling in the hands. During the same period she has gained weight; complains of snoring, and occasional daytime somnolence.
Her shoe size had increased from size 7 medium to size 8 double-wide, her ring size had also increased, and she thought that her nose had become larger.
She shows you pictures and cries as she tells you she does not recognize herself anymore and feels like “Princess Fiona”
No other medical history. Medications include acetaminophen as needed.
which pair of hormones normally is responsible for these changes?
somatostatin and GH
she has acromegaly
what test would you order to help diagnose acromegaly?
IGF-1 levels; will be elevated with acromegaly
glucose tolerance test and sleep study tests can be done after you make the diagnosis to see what changes have been caused in the body due to the acromegaly like worsening DM or sleep apnea or carpal tunnel
after that you would probably also want to get a pituitary MRI because a pituitary adenoma is the most likely cause – if the MRI is negative then where is the GH coming from? you would do a CT of the abdomen and chest to see if there was an ectopic secretion of GH
you would never do a random GH because it’s always fluctuating throughout the day
so basically do biochemical testing first then do imagining
if MRI imagining shows a pituitary adenoma with symptoms of acromegaly, what is the next step in management? surgery, radiotherapy or octreotide?
surgery
you need to decrease GH levels to relieve acromegaly symptoms and whether it’s a micro adenoma or macro adenoma you need to remove the bulk of the tumor
octreotide is used after surgery if there’s still elevated levels of GH
so this is different than a prolactinoma which is treated medically with dopamine antagonists
24-year-old female with no medical history delivered a healthy baby at 40 weeks of gestation. She presented to your clinic because she has been unable to breastfeed her baby despite all recommendations given by lactation specialist.
Upon further questioning she states she feels very tired but believes is related to lack of sleep and has not had menstrual period.
Her delivery was complicated.
what is the most likely diagnosis?
sheehan syndrome
secretion of which pituitary hormone may be affected in a woman with Sheehan syndrome?
ACTH, TSH, prolactin and GH
they present with hypopituitarism postpartum
which hormone is the most important to replace in a patient with Sheehan syndrome?
TSH and cortisol
give hydrocortisone first though; you don’t want to replace with levothyroxine till you’ve fixed the cortisol level
if you’re concerned a patient has pituitary apoplexy what would be the clinical presentation?
dry skin, amenorrhea, fatigue, low BP, after pregnancy
usually more acute
An 19-year-old man presents with increased thirst and frequent urination over the previous 10 weeks.
He wakes up 5 to 6 times a night to urinate and drink water.
He reports frequent headache, blurred vision, fatigue, weight loss (10 lb [4.5 kg]), and nausea.
He was previously healthy. He takes no medications.
On physical examination, he is normotensive and afebrile. His height is 70 in (177.8 cm), and weight is 141 lb (64.1 kg) (BMI = 20.2 kg/m2). There is limitation of upward gaze and a left temporal visual field defect on confrontation. The thyroid is normal. Testicular size is 10 mL and the testes have no palpable masses. Muscle strength is normal.
Routine chemistry done recently shows serum sodium 144
brain MRI shows pituitary lesion and a pineal mass
what is the most likely diagnosis?
germ cell tumor
germ cell tumors in young people can present with DI!
where is ADH primarily produced?
supraoptic nucleus and paraventricular nucleus of the hypothalamus
then they’re stored in the posterior pituitary
on the other hand, in the anterior pituitary, hormones are both produced and stored there
