Functional and Nonfunctional Pituitary Tumors

Medical Intel

Some pituitary tumors need immediate treatment, while others may benefit from a wait-and-see approach. Dr. Susmeeta Sharma discusses the different types of pituitary tumors and how we care for them.

TRANSCRIPT

Intro: MedStar Washington Hospital Center presents Medical Intel where our healthcare team shares health and wellness insights and gives you the inside story on advances in medicine.

Host: Thank you for joining us today. We’re talking with Dr. Susmeeta T. Sharma, director of pituitary endocrinology at MedStar Washington Hospital Center. Welcome, Dr. Sharma.

Dr. Susmeeta T. Sharma: Thank you for having me.

Host: Pituitary tumors often cause no symptoms, but when they do, the symptoms typically are vague and easily can be mistaken for other less serious conditions. Pituitary tumors may be functional, which means they secrete excess hormones, or non-functional, which means they do not secrete excess hormones. Dr. Sharma, when symptoms occur, what do patients typically experience?

Dr. Sharma: The symptoms of pituitary tumor kind of depend on the size of the tumor and whether it’s a functional tumor, what hormone it’s making, is it causing any hormone deficiency. So, I always think that in order to understand what symptoms a pituitary tumor can cause you have to understand the basic physiology and anatomy of a pituitary gland. So, the pituitary gland is a pea-sized gland located at the base of the brain. And I think of it as a conductor of an orchestra. It basically makes a bunch of different hormones, which then regulate other endocrine glands in the body to make other hormones. So, for example, it makes TSH (thyroid stimulating hormone) which then acts on the thyroid gland to make thyroid hormones. It makes ACTH (adrenocorticotropic hormone) which then acts on the adrenal glands to make...regulate cortisone production. It makes prolactin which acts at the level of the breast for development of the mammary glands and milk production. It makes FSH and LH which are gonadotropins which act on the gonads, ovaries, and testes to make female and male gonadal hormones, testosterone and estrogen. And then it also makes growth hormone which really acts on the entire bodies involved in growth, especially in children during puberty, achieving, uh, their full height potential.

So, it’s a really important gland and any small, uh, dysfunction, whether it’s related to an inflammatory disorder or a tumor that’s causing compression - any of that can lead to either hypofunction of one of these hormones or increased function of one of these hormones. A pituitary tumor has the potential to make any of these hormones. So, it’s...if it’s a functional pituitary tumor, it can cause symptoms related to excess prolactin, which will then be breast milk production or irregular menstrual cycles or infertility in a female. In a male it may be even harder to detect because of the lack of the menstrual irregularity as a symptom so while they may present with is decreased libido. And later on, as the tumor grows, it may cause symptoms related to the size of the tumor, so headaches and vision problems. So, it all depends on the kind of hormone that the pituitary tumor is making. Another example would be if it’s making ACTH which is then leading to excess cortisone production that can lead to a patient gaining a lot of weight, muscle weakness, fractures, diabetes, high blood pressure, developing purple stretch marks on their body. So, a variety of symptoms that could be related to excess production of a particular hormone in the body. Uh, so that would come from hormonal excess. But then you could have symptoms related to hormonal deficiencies. So, if the tumor is large enough that it’s compressing normal pituitary cells, you could have a low cortisol state, a low growth hormone state, a low thyroid hormone state, which can then lead to other symptoms of their own. And lastly, like I mentioned earlier, from the size of the tumor. Even if it’s not producing any hormone, as the tumor grows, by the size of the tumor, it can cause headaches to the patient and also, in the space where the pituitary gland is located, it’s a very tight space and it’s very close to the optic nerve or the optic chiasm, and those are fibers that control our vision, especially our peripheral vision, and so, as the tumor grows, it can compress on these nerve fibers, leading to vision problems - double vision, loss of peripheral vision - it may manifest as that. Many times though it may be the patient may not have any symptom at all and it may get detected on an MRI done for other reasons - for example, for headaches, for...which are...may or may not be related to the pituitary tumor. So, the presentation can really be varied and depends on how big the tumor is and if it’s making any particular hormone.

Host: When symptoms arise, is treatment urgent, or do the tumors grow slowly?

Dr. Sharma: The majority of these tumors are slow growing tumors. These are benign tumors, not cancers. Often, patients may hear a diagnosis of brain tumor but this is very different from other tumors that arise in the brain and that have a much higher malignant or a cancerous potential. So, pituitary cancer is very rare and so these are mostly benign tumors. Benign in the sense of them being cancerous but not benign in some of the effects that they can cause if they go undetected. But most of the time, yes, given the fact that these are slow growing tumors, the symptoms often develop gradually. Uh, many times these symptoms can be non-specific so a patient may just have some fatigue and some inability to lose some weight and that could even be a symptom for a hormonal disorder. So, um, sometimes the presentation may be very obvious, very florid, and we may even walk into a room and see a clinical appearance of a patient and think that, “Oh, this patient has to have a pituitary hormonal disorder” while other times it may need a much more lengthy interview in the clinic and exam and for the blood test before a diagnosis can be made.

Host: What are some of those immediate symptoms that would cause you to think a patient you’re visiting with has a pituitary issue?

Dr. Sharma: Um, so, in particular in women, if they have irregular menstrual cycles and there is breast milk production and they have not had a baby and so that would be a situation where there has to be a prolactin elevation in the majority of the cases. Uh, that may or may not be related to a pituitary tumor; that there are other disorders that can cause a prolactin elevation. But that definitely means that they need to be evaluated by an endocrinologist and need to be tested to see if there is a pituitary disorder there. So that would be one example. Other times, especially in conditions where the pituitary tumor makes growth hormone or the hormone ACTH (adrenocorticotropic hormone) which then leads to cortisol excess—those two particular hormonal disorders can often present very floridly, where the clinical appearance can be very dramatic and easy to detect if it has gone undetected for quite a period of time. So, for example, a growth hormone secreting tumor or excess growth hormone leads to enlarged, fleshy hands and feet. The patient would complain of change in ring size, change in shoe size. They would have changing facial features, coarsening facial features over time that one can detect on...while examining or looking at the patient. Another example would be Cushing’s Syndrome, or excess cortisol in the body. In that, also you have a change in facial features, rounding of face, a reddening of face which we call plethora, excess fat positioned on the upper back of the body in the base of the neck area where...near the clavicles. And so all of that can make us at least suspect that this patient could have Cushing’s, and then those patients would need to be screened for that disorder.

Host: What are some of the common diagnostic tests when a doctor suspects a pituitary disorder?

Dr. Sharma: If we suspect that a patient has pituitary disorder, sometimes the clinical presentation is so florid that we may want to test for a particular hormone and other times we may need to test for all of the pituitary hormones. And again, anytime I am thinking of a pituitary tumor, I need to make sure both that A) the tumor is not making any excess hormones, so those would be blood and urine tests to start off with for these particular various hormones and then I also need to make sure that it is not deficient. Many times, the blood and urine tests may not itself be sufficient for the diagnosis - that would be the initial screen, followed by some more dynamic testing that may need to be done to confirm that their patient has a particular hormonal deficiency or hormonal excess. And then again, we need to have sophisticated MRI to be able to detect the full location of the tumor, and then you need to collaborate with the neuropthamologist to make sure we are looking at any possible visual deficits related to the pituitary tumor. So definitely a team work - you need the endocrinologist to be able to assess for these hormonal deficiencies and hormonal excess disorders, you need the neuropthamologist and the neuroradiologist to look at...um, visualize the tumor on the MRI and assess if there are any visual field deficits related to the tumor, and then we need, of course, the neurosurgeon if surgical treatment is indicated.

Host: What is the approximate size of the pituitary gland?

Dr. Sharma: In a three-dimensional structure, the height of a normal pituitary gland is around 6 millimeters in size so, overall again, yeah, the pituitary gland is about the size of a pea. And then, any time there’s a tumor within it—so just a few millimeters above is the optic chiasm and so any time the tumor is growing there is a potential of that gland with the tumor encroaching onto the eye nerves, especially if the tumor is greater than a centimeter, which is what we call a macroadenoma while in the centimeter. When the pituitary tumor is less than a centimeter it’s called a microadenoma.

Host: How big are the tumors that you’re taking care of in these patients?

Dr. Sharma: So, very variable. So microadenomas, may come to our attention two ways. It might just be that in this era of MRIs, an MRI is done for other reasons and we find a small tumor now. Once the tumor is found, you do want to make sure that it’s not making any hormones and then you have to follow it once a year, at least, to make sure that it’s not growing significantly in size that it needs surgical attention, just based on the size of the tumor. Otherwise, it may be that it’s a small tumor but it’s making a particular hormone so mostly functional tumors can get detected at a smaller stage just because of...they’re causing much more symptoms to the patient from the hormonal excess related to them. And so functional tumors may get detected at a size when they’re less than a centimeter. Non-functional tumors though, most of the time if they’ve not been incidentally detected on an MRI, would be greater than a centimeter. So, we have had tumors that are 5 to 6 centimeters, especially many times in patients who have not sought medical attention or have not been seeing physicians regularly. Um, other times the tumor could be very large but it’s just that the patient has not paid attention to the visual field deficit that it may be causing. So, they just get used to not being able to see peripherally and that can be very dangerous, especially if they’re out there driving with the visual defect. So, as an example, we had a young male with a prolactin secreting tumor. And so, this tumor was about 5 centimeters in size. And, these are slow growing tumors so it was probably present for several years but a prolactin secreting tumor in the male, all it was doing in his case was lowering his testosterone levels and thereby probably causing decreased libido but it had to grow to that big a size and to finally, during a testing for a DMV related driver’s license, he failed his vision exam and that’s how his visual field loss initially came to attention.

Host: Is a functional or a non-functional tumor more dangerous?

Dr. Sharma: A non-functional tumor, whether or not it needs immediate attention, would depend on the size of the tumor and what mass effects it’s causing. But definitely a functional tumor always needs attention. So, I’m not sure if one is more serious than the other but definitely a functional tumor always needs attention immediately. And so, uh, most functional tumors, actually the first line of treatment would be surgery. The only functional tumor that can be purely treated medically in the majority of the cases is a prolactin secreting tumor. So, although there are medications available for treating various different functional tumors, in prolactin secreting tumors using medications that are available are so effective that we can actually shrink the pituitary tumor and normalize the prolactin levels with medications alone and they don’t need surgery. And, in fact, outcomes from medical treatment can even supersede what we can achieve surgically and so that is why an endocrinological evaluation is really important for pituitary tumors because we want to make sure that we assess whether or not surgery is indicated and also make sure we’re not missing these, this particular kind of tumor—the prolactin secreting tumor—where we can make a difference medically instead of the patient having to undergo any unnecessary surgery.

Host: When a patient requires surgery, is there a minimally invasive option?

Dr. Sharma: Surgical techniques for pituitary tumors have really advanced. And the majority of the pituitary tumors can be safely resected through the transsphenoidal route. So, we have an endoscopic or a microscopic approach and it depends on the size and location of the tumor when the pituitary surgeon decides which approach to take, but they’re all being done minimally invasively now. And so, this would be a route either under the lips sublingually or trans nasal so through the nasal passage, through the sphenoid sinus and then through the base of the sella, which is what we call where a pituitary gland is located. So, that would be a minimally invasive approach. Patients are usually in the hospital for 2 to 3 days after surgery and are able to leave so compared to the earlier times where you would actually have to cut open the skull and then approach a large pituitary tumor. So even tumors of the size of 5 to 6 centimeters can be safely removed through this route these days.

Host: Is there any scarring related to the surgery?

Dr. Sharma: So, no actual visible scarring. Many times, in the path that the surgeons take, you may have some superficial nerve fibers that are affected and so people may have temporary, um, either altered or loss of taste or smell sensation. They’re definitely going through the sinus so sometime you can have sinus-related issues but those are usually temporary and there’s, uh, no visible scarring. You can’t really tell that the patient has had surgery, in fact.

Host: Why is MedStar Washington Hospital Center the place for people to seek care?

Dr. Sharma: Oh, I think what we provide is a multidisciplinary team approach. It’s really important to see a patient and treat them as an individual and see what would be the best treatment option for them. So, any time I think of a pituitary tumor, I think what it needs is a team and not just a single physician operating in isolation. So, you need an endocrinologist to evaluate the hormonal excess or deficiency related to the pituitary tumor. You need a neuroradiologist to properly evaluate the tumor and make sure they’re using up to the mark MRI techniques and developing newer localization techniques for that. A majority of the tumors do need to be surgically removed so we definitely need an experienced neurosurgeon. Not every neurosurgeon is doing the number of transsphenoidal surgeries I feel that are necessary to develop the expertise, so it’s really important to have an experienced neurosurgeon who does a lot of these. And we are lucky to have Dr. Edward Aulisi as one of our neurosurgeons here. And so, an experienced neurosurgeon and then an experienced neuro-opthamologist to look at visual field deficits related to it. And then as an adjunct treatment, other than surgery and medical therapy, you may also need radiation therapy for the pituitary tumor. So, we have focused stereotactic radius surgery options available at MedStar Washington Hospital Center as well. So, having it all under one roof helps because we all are communicating and trying to develop a treatment plan that is best for the patient...that’s optimal for the patient.

Host: Are you currently doing any research on pituitary tumors that you’d like to share with people in the community?

Dr. Sharma: So, we are starting the research process. We do have Dr. Joseph Verbalis, who’s at our counterpart institute which is Georgetown University Hospital, where he’s already doing a lot of research on posterior pituitary and sodium disorders. And then Washington Hospital Center - we are developing other research programs to look at the path of physiology of tumors so what leads...for different patient populations to develop various kinds of pituitary tumors. We are working with our pathology department to try and see what molecular markers we can identify to better, um, identify what treatment option would be better for a particular patient based on those molecular markers. And then, of course, devising better, more refined surgical techniques for making these surgeries possible in a minimally invasive manner.

Host: Thank you for joining us today, Dr. Sharma.

Dr. Sharma: Thank you for having me.

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