The two topics I’m doing today are both about diseases of the pituitary. This one, is pituitary diseases in general; and the other will be the predominant diseases of the pituitary which are the pituitary adenomas.
So, pituitary diseases in general first.
What is Pituitary Disease?
If this is ailing you, you either have something like headaches because of the mass effect of the pituitary disease, or you have some endocrine effect of the disease like fatigue or some other metabolic disorder because the pituitary is responsible for so many hormones. So, you will either need a neurologist or an endocrinologist. Or both. And oncologist, neurosurgeon. You’re going to need a lot.
But you will usually present to the emergency department. Those emergency physicians know this work up like the back of their hand. Trust them.
What is the Pituitary Gland and Where is it Located?
The pituitary or master gland is located in a very confined space of the brain. As such, it’s diseases will render harm in either very infiltrating or very local ways.
Because the pituitary is so vascular, It is susceptible to vascular fluctuations, especially if they are dramatic. So diseases of the pituitary can be vascular and nonvascular.
Is Pituitary Disease and Adenoma Malignant?
Furthermore, diseases of the pituitary can be broken down into malignant and non-malignant. Malignant can mean low tissue differentiation, so a propensity to spread rapidly. Malignant can also mean “bad” because of the location of the problematic pituitary – the brain. So, if one type of pituitary cell is having a problem (and there are many types of pituitary cells), it is likely to affect the function of the other pituitary cells even if they are not diseased. Further still, a pituitary problem can affect tissues adjacent to/outside the pituitary. Some pretty significant structures around there: Nerves, arteries, sinuses, and the brain encasing itself, the dura, hurts if it is compromised. Hence, headaches.
Signs and Symptoms of Pituitary Disease
A patient having a pituitary problem can complain of tunnel vision called bilateral temporal hemianopsia, a term that implies that you have temporal visual field cuts (note it has nothing to do with the temporal lobe at all by the way!). This occurs because the nasal fibers of optic chiasm cross right over the pituitary superiorly. So if the pituitary is having problems that are extending northward, it will hit the chiasm, namely the nasal fibers first. Since the nasal fibers are crossing over there, the actual visual field cut once they reach the cortex of your brain will actually be the outside visual field areas, known as the temporal field areas just because of their peripheral positioning. Hence, temporal visual fields cuts can occur because of central superior bulging of an ailing pituitary into the optic chiasm.
Headaches can occur as mentioned above because the dura being encroached. Also, meiosis can occur in your pupils because of cranial nerve impingement by a growing pituitary pathology. Other cranial nerve motor palsies can occur as a result of other cranial nerve encroachment. Cavitary sinuses can be compromised by growing pituitary mass, evidenced by spinal fluid coming out of your nose (NOT a good situation). Sinus symptoms can also occur like sinus headaches.
After the appropriate work up, your physician can order a CT or MRI. Because the pituitary is hanging from a slender stock, if the tumor or pathology grows on the punching bag, it can extend into the slender stock to the upper brain, giving a snowman type of appearance on the imaging. The “snowman“ sign is thus a constriction that can occur at the pituitary stock as it courses through the sela (turcica).
And lastly, pituitary problems can be divided into secretory and nonsecretory. As these terms imply, some pituitary problems lead to increased secretion of the hormones those cells produce; other pituitary problems will lead to decreased secretion of important hormones. So in these conditions, endocrine changes will be noticed, metabolic rate, energy, libido, and others.
What are Pituitary Disorders?
In summary, if you have a pituitary disorder, this will be the general breakdown of the possibilities:
- Infiltrative versus local
- Vascular versus avascular
- Malignant versus benign
- Large compromising rest of pituitary f. plus local structures; versus small
- Hypersecretory versus hyposecretory