Pituitary tumors
Childhood pituitary tumors, although rare, do occur. Such tumors are usually
benign, that is, non-cancerous. However, because the pituitary gland is very
important in helping to regulate the hormones of the body, even a small
disruption can have serious effects on mood, on the ability to focus and
concentrate, as well as on growth and overall maturation. Pituitary tumors can
also cause symptoms due to pressure on other parts of the brain and may cause
headaches, dizziness, or problems with vision.
Symptoms
In general, the symptoms seen with pituitary tumors are related to a
disturbance in production of a specific hormone or group of hormones and relate
to the role the hormones play in maintaining health and development. The
symptoms of pituitary tumors vary depending on the size and location of the
tumor and whether the tumor presses on other organs or affects the secretion of
hormones. For instance, pituitary tumors may press on the optic nerve, causing
problems with vision.
The symptoms of a pituitary tumor can range from simple common complaints
such as listlessness or restlessness to more severe symptoms such as headaches,
vomiting or dizziness. One problem in determining whether or not a tumor is
present is that every child has minor and relatively unimportant symptoms such
as restlessness or headaches from time to time. Of course, when more distressing
signs or multiple symptoms are seen, parents and doctors search for an
explanation and more precise tests are recommended.
In older children or adolescents, other signs may be seen including problems
with normal growth and development. For instance, sometimes young girls or boys,
under age 9, experience a very early puberty, referred to as precocious puberty.
This is caused by tumors that secrete luteinizing hormone (LH). Girls may
develop breasts, have pubic hair, and begin menstruation. Boys may find their
genitals enlarging and facial and pubic hair beginning to grow. Tumors that
secrete follicle stimulating hormone (FSH), in contrast, can retard sexual
development in both sexes and stunt growth.
If the tumor limits the secretion of gonadotropin, it can affect the
development and functioning of the ovaries and testes. Adolescent boys may fail
to enter puberty or may lose facial or pubic hair and notice an effect on their
genital size. Adolescent girls may also fail to enter puberty or may find their
breasts ' smaller, some loss of pubic hair, and perhaps an interruption of
menstruation.
Where secretion of adrenocorticotropic hormone (ACTH) is low, the child can
experience low blood sugar, fatigue, and low blood pressure, which can cause
dizziness when standing. On the other hand, with pituitary tumors that secrete
ACTH, a variety of problems can result. These include stunted growth, delayed or
stopped puberty, weight gain, acne, purple streaks in the skin, a round red
face, and a bulge of fat on the back of or below the neck. These tumors can also
cause weakness, depression, or forgetfulness and trigger a sudden complete or
partial loss of vision.
Some pituitary tumors can disrupt the function of the thyroid gland by
secreting thyroid stimulating hormone (TSH). This in turn enlarges the thyroid,
causing a visibly large lump in the neck known as a goiter. These tumors also
cause nervousness, a rapid pulse, weight loss, excess eating and sweating, and a
sensitivity to heat.
Pituitary tumors that limit the secretion of TSH can also affect a child in
many ways, including making it harder to concentrate, tiredness, constipation,
dry skin, and a sensitivity to cold. It may also cause girls to have irregular
periods or not to menstruate at all.
Some pituitary tumors decrease the secretion of vasopressin, the hormone that
triggers the kidney's reabsorption of water from urine. A lack of vasopressin
can cause a great thirst, excess urination, voracious appetite accompanied by
emaciation, loss of strength, and fainting.
Other pituitary tumors secrete an excess of the hormone prolactin. In girls
who have gone through puberty, tumors that secrete the hormone prolactin can
cause the production of breast milk and stop menstruation, while in
post-pubertal boys they can cause impotence. An excess of prolactin can also
delay or stop puberty in both sexes.
A pituitary tumor that limits the secretion of growth hormone (GH) can stunt
the growth of children and cause low blood sugar, which can induce fainting,
dizziness, anxiety, and intense hunger. Growth hormonesecreting tumors in
growing children can boost growth excessively so that, if not treated, the
children can grow unusually tall.
In adolescent children who have gone through puberty, and whose bones have
stopped growing, excess GH can cause enlargement of their feet, hands, lips,
nose, and jaw, a condition referred to as acromegaly It also can foster excess
perspiration and fatigue, a widening of the spaces between the teeth, furrows in
the forehead and weakness in the hands.
The most common type of pituitary tumor in children is due to growth of
embryonic remnants in the area of the pituitary gland and is called
craniopharyngioma. This tumor often disrupts vision by pressing on the optic
nerve. Craniopharyngiomas also cause a lack of most pituitary hormones,
prompting a combination of some of the symptoms previously described for tumors
that induce a deficiency of single pituitary hormones.
Diagnosis
Doctors can detect larger pituitary tumors on an x-ray, computerized
tomography scan or magnetic resonance scan. Many pituitary tumors, however, are
too small to be seen on these images of the pituitary region of the brain. To
diagnose these tumors, doctors try to detect the hormonal abnormalities with
various tests. Often blood or urine levels of specific hormones are measured
within a few hours of giving the patient compounds known to stimulate or
suppress production of the hormones.
For instance, sometimes patients are given a glucose tolerance test. After
fasting overnight, the patient drinks a sugar solution, then has blood samples
taken in which sugar or growth hormone levels are measured. Sometimes, in order
to locate a very small tumor in the pituitary gland, an invasive procedure is
required. This procedure is called inferior petrosal sinus sampling. A
radiologist inserts special catheters from the groin veins into the vessels that
drain the pituitary gland at the top of the neck and draws blood for measurement
of the hormone that the tumor secretes.
Treatment
Doctors can successfully treat most pituitary tumors with microsurgery
performed under the magnification of a surgical microscope, radiation therapy,
surgery, drugs, or a combination of these treatments. Surgery is the treatment
of choice for tumors that enlarge rapidly and threaten vision. The treatment
plan for other pituitary tumors varies according to the type and size of the
tumor.
Depending on each individual diagnosis, a physician can prescribe a wide
variety of treatments. Sometimes treatments stimulate or compensate for missing
hormones, others reduce the production of hormones. In some cases, drugs must be
taken on a daily basis.
Questions and referrals can be directed to (717) 531-0857.
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