Prolactinoma – causes, symptoms, diagnosis, treatment, pathology

With prolactinoma, prolactin refers to the
endocrine hormone secreted by the pituitary gland and -oma refers to a tumor. So a prolactinoma is a benign tumor, or adenoma,
of the pituitary gland that secretes excess prolactin. Normally, the pituitary is a pea-sized gland,
hanging by a stalk from the base of the brain. It sits just behind the eyes near something
called the optic chiasm, which is where the optic nerves cross. The anterior pituitary, which is the front
of the pituitary gland, contains a few different types of cells, and each of which secretes
a different hormone. One group of cells in the anterior pituitary
are called lactotrophs and they secrete prolactin. Prolactin stimulates breast milk production. Another group of cells are the gonadotrophs
and they secrete two gonadotropic hormones – luteinizing hormone, or LH, and follicle-stimulating
hormone, or FSH, both of which stimulate the ovaries in women which make estrogen and stimulate
the testes in men which make testosterone. Prolactin release is controlled by something
called the hypothalamus, which is a structure at the base of the brain just above the pituitary
gland. It makes two key hormones, thyrotropin-releasing
hormone which increases prolactin release, and dopamine, which inhibits the prolactin
release and actually overrides the stimulatory effect of thyrotropin-releasing hormone. That’s why dopamine is known as prolactin-inhibiting
factor, and why it’s constantly released to prevent prolactin release in anyone that’s
not pregnant. High levels of prolactin in the blood sends
a negative feedback signal to the hypothalamus, making it release more dopamine which then
decreases prolactin levels. High levels of prolactin can also signal the
hypothalamus to decrease the secretion of gonadotropin releasing hormone or GnRH. Gonadotropin releasing hormone acts on the
anterior pituitary to make follicle stimulating hormone and luteinizing hormone or FSH and
LH. Now, during pregnancy the anterior pituitary
gland releases prolactin and the placenta releases human placental lactogen and progesterone,
and all three of these hormones stimulate the growth of more glandular tissue in the
breast to produce milk. Prolactinomas are functional tumors, meaning
they secrete high levels of prolactin, and they typically form when there’s a mutation
in the lactotroph cells of the anterior pituitary that allows the cells to divide uncontrollably. The key is in the size of these things. Prolactinomas that are less than 10 mm in
diameter are considered microprolactinomas, whereas those greater than 10 mm are known
as macroprolactinomas. Now, macroprolactinomas can compress surrounding
structures like the meninges, which is the protective layer overlying the brain and that
typically causes pain when it’s stretched. Also, an enlarged pituitary gland can compress
the optic nerves as they cross at the optic chiasm. This can cause visual problems as well as
affect a person’s ability to view things that are in the temporal, or the outermost
portion, of the visual field in both eyes, and this is called “bitemporal hemianopia”. Another name for this is tunnel vision because
the center of your vision is clear but everything in the periphery is dark, kind of like looking
through a tunnel, I suppose. As well as all the local effects, the prolactin
that gets secreted by the pituitary inhibits the hypothalamus from releasing gonadotropin
releasing hormone, which leads to a decrease in follicle stimulating hormone and luteinizing
hormone from the pituitary. This results in less estrogen being produced
in the ovaries, and less testosterone from the testes. Low levels of these sex hormones can cause
inhibition of ovulation in women, and inhibition of spermatogenesis in men. In women, estrogen is also really important
because it prevents the activation and differentiation of bone cells called osteoclasts. Osteoclasts normally break down bones and
release the calcium into the blood. So with decreased estrogen levels, osteoclasts
are free to proliferate and therefore women with prolactinomas are at an increased risk
of fractures and osteoporosis. So, when it comes to symptoms people with
small prolactinomas, or microprolactinomas, often have no symptoms at all, whereas those
with large prolactinomas, macroprolactinomas, might have vision problems, like bitemporal
hemianopia, or headaches where the meninges are stretched. In women, excess prolactin causes galactorrhea,
which is a milky nipple discharge, amenorrhea, which is missed menses, vaginal dryness, and
brittle bones in old age. in men, excess prolactin causes gynecomastia or breast enlargement
and erectile dysfunction. And both sexes can experience decreased libido
and infertility. The diagnosis of a prolactinoma is typically
based on elevated levels of prolactin in the blood. Sometimes there’s also excess thyrotropin-releasing
hormone which may be stimulating the pituitary gland to secrete prolactin. Often, an MRI can be done to visualize the
prolactinoma and classify it based on size. To treat prolactinomas you can use medication
or chop it out surgically. Since dopamine inhibits prolactin release,
a clever way to treat it medically is with dopamine agonists like bromocriptine and cabergoline
can be used to inhibit prolactin release. Now, surgery is usually only considered for
individuals with macroprolactinomas or in individuals who fail medical therapy. If complete resection of the prolactinoma
is not possible or if prolactin levels remain elevated after surgery, radiation therapy
can sometimes be useful. OK, we made it, that’s it. So let’s just quickly whizz over the main
points – Prolactinomas are benign tumors of the anterior pituitary that result in the
excess secretion of prolactin. Excess prolactin can cause a wide range of
symptoms including galactorrhea, which is a milky discharge from the nipples, gynecomastia,
which is breast tissue growth in men, amenorrhea, or missed menstrual periods and infertility. It is typically treated either with dopamine
agonists or with surgery.


  1. you're 3 weeks too late!
    your videos helped me a lot tho ! i got a pretty good score thank you so much , you are my favorite channel 😘

  2. I have prolactinoma. I discovery whe I try to get pregnant. I took parlodel without result. But in one month of carbecolin ( pretty expensive tratamento cover by public health on brasil) I got pregnant. I don’t have problem to get pregnant. My tumor have a lil bit more than 100mm but it’s just on control. I don’t took any medications nowadays. And I don’t know if I can get pregnant again. Nowadays I have 2 kids. I discovered tumor 15 years ago. I think on surgery and radiotherapy… but everything goes right….

  3. I think the precise way is to say that TRH only in high levesl stimulates prolactin release as in hypothyroidism…

  4. I love your accent and the videos. Quick question, are all these videos and flashcards available free of charge?

  5. in the 3:30, instead of bitemporal "hemianopia", isn't "hemianopsia" a right word? Thank you guys for excellent videos, by the way!

  6. Its been 3 months I am taking cabergoline for lowering my prolactin level that was 249 ng/ml but after two months my prolactin level lowered to 8 ng/ml. First month i got my periods on 33th day of my cycle… nd now I dont get my periods and its 51th day of my cycle. I did home pregnancy teststhey all came negative. And 10 days back I did blood pregnancy test and it was came negative too. I am so confused and a bit worried as I came to know that this medicine help in regulation of periods. But I dont know what is this..does anyone has ever go through the same?

  7. I prefer the North American male voice over. The script is more casual with him and he's more natural at it in my opinion.

    There were a lot of "now" in this script and very monotonous and not very engaging, "kind of like looking through a tunnel I suppose", "Okay, we made it, that's it" sounded exactly like the rest of the video, painfully hammy, the latter made it unnecessarily obvious it was an ordeal which is exact opposite of what these videos are meant to be. If you're going to make it fun the voice over ought to sound convinced itself.

  8. Hi Team Osmosis! I Thank you very much for these videos! They really really helped me cope with my medical studies. Do you you have the scripts of your videos?

  9. I have all the sypmtoms but my exams keep.coming.out.normal.i have a hump on my.upper back.and neck.have had my period in a yesterday.and have eye.pressure.for.2,yrs.

  10. u are very good but very very fast . be a little slow. kaplan video speed. .as its difficult to imbibe. repeat n rerepeat .

  11. I have been watching osmosis vids for a long time now and I love it all! But this video I feel that had a perfect speed of speech. So pls if you pass on the message do tell to keep the speed of vid like this.

  12. Than you. I had a Prolactinoma in the 90's. I was cured with Bromocriptine over a couple of years. What was interesting was the fact my GYN discovered the tumor and he found a Endocrinologist to cure it. Before the GYN and the Endo, a Psychiatrist described my disorder (mood) as Bipolar Affective Disorder. I was forever marked as having a psychiatric disorder which resulted in restrictions in my chosen profession in the legal field… I can only go so far. Devastating. Such is life to have a misdiagnosis/judgement ruin your life forever.

  13. good video but as a male, I felt like the effects of low testosterone were left out vs the explanation of low estrogen in females.

  14. My husband was diagnosed with this, and it went treated for so long because nobody could figure out what was bothering him. It wasnt until he got an MRI that the doctor found the tumor.

  15. Thank you for this video. I am currently waiting on a blood test that will read prolactin / other hormone levels. I had precocious puberty at 6, my parents ordered an MRI that did not show anything wrong at the time. i also have an irregular period, sometimes it is a month long, then it can go away for 3 months, and come back for 2 days. Also producing breast milk, and i've never been pregnant. i don't know what else it could be, it must be this. hopefully an mri will catch something this time around

  16. I had only high prolactine and low D vitamin, I have hudge hair loss.
    Do you think prolactin can be cause of hair loss ?
    I don't have tumor or smthg like that.

  17. Why can't it be left alone? It doesn't seem dangerous. I am just asking. Thank you.

    I have it…3 years now. My symptoms are a bit nontraditional. The two main ones are massively heavy, non-stop periods, milky breast discharge, and apparent extreme hair growth on my head; the hair everywhere else has fallen out.

  18. Thank you so much for such a precise and well done video! I've learnt a lot, really curious about my final diagnosis

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