Gigantismo

1. UNDERSTANDING THE BRAIN: THE
NEUROBIOLOGY OF EVERYDAY LIFE
GIGANTISM AND ACROMEGALY
Carolina Elizabeth Chavez Rodriguez
Aguascalientes, Ags. México
22 de agosto del 2023

2. The pituitary gland is a pea-sized gland found at the base of the brain. The
pituitary is the "master controlgland" - it produces hormones that affect
growth and the functions of the other glands in the body.
A disease of the pituitary gland can cause the productionof too few or too
many hormones. Some injuries can cause disorders of the pituitary gland, but
the most common cause is a tumor.
Gigantism and acromegaly
GH (growth hormone) stimulates somatic growth and regulates metabolism. Growth
hormone-releasing hormone (GHRH) is the main stimulator, and somatostatin is the main
inhibitor of GH synthesis and secretion. In turn, GH controls the synthesis of insulin-like
growth factor-1 (IGF-1, also called somatomedin-C), which primarily controls body growth.
Although IGF-1 is produced by many tissues locally, the liver is the main source of
circulating IGF-1. The metabolic effects of GH are biphasic. Initially, GH exerts effects
similar to those of insulin, with increased glucose uptake in muscle and adipose tissue,
stimulation of amino acid uptake and protein synthesis in the liver and muscle, and inhibition
of lipolysis in adipose tissue. Several hours later, more profound anti-insulin-type metabolic
effects occur. These include inhibition of glucose uptake and use, which increases blood
glucose and stimulates lipolysis, which in turn leads to increased plasma free fatty acid
concentrations.
GIGANTISM
This rare disorder develops when GH hypersecretion begins in childhood, before epiphyseal
closure. In these patients, the rate of bone growth and final height increase, but with little
bone deformity. However, edema of the soft tissues occurs and the peripheral nerves are
enlarged. Delayed puberty or hypogonadotropic hypogonadism also frequently occurs,
leading to a eunuchoid habitus (ie, a body build that is tall and slender with long limbs).
PHYSIOGNOMIC CHANGES AND SYMPTOMS

3. 1. Facial features accentuated by growth of the facial bones.
2. Increase in the size of the lower lip and nose.
3. Separation of the teeth (diastasis) and enlargement of the jaw (prognathism).
4. Enlargement of the tongue (macroglossia).
5. Deeper voice.
6. Thickening and edema of the eyelids.
7. Exaggerated growth of the hands, feet and fingers.
8. Oily skin and increased pore size.
9. Hyperpigmentation or acanthosis nigricans.
10. Acrochordomas.
11. Excessive sweating (hyperhidrosis).
12. Overweight or obesity.
13. Peripheral neuropathies (carpal tunnel syndromes or others).
14. Arthropathy: manifested by pain, inflammation and reduced mobility of multiple
joints.
15. Excessive increase in body height for age (only in gigantism).
Here are some common treatments for acromegaly and gigantism:
Surgery: Surgery to remove the pituitary gland (transsphenoidal adenomectomy) is often
the treatment of choice for acromegaly and gigantism. If the entire adenoma is removed,
growth hormone levels may return to normal. In some cases, it may be necessary to
perform additional surgery or use radiation therapy to control the growth of the tumors.
Radiation therapy: Radiation therapy can be used to kill tumor cells that make growth
hormone. It may be an option if surgery is not possible or effective, or if a complementary
treatment to surgery is desired.
Medications: There are medications that can reduce the production of growth hormone or
block its effects. Medications include somatostatin analogues, such as octreotide and
lanreotide, which reduce GH production; and growth hormone receptor antagonists, such as
pegvisomant, which block the effects of GH.
These drugs may be helpful in people who are not candidates for surgery or in those whose
tumor cannot be completely removed.
Is acromegaly hereditary?
acromegaly can sometimes affect several members of the same family due to genetic
changes, or mutations, in your DNA. Some of these mutations have been identified, for
example, the gene AIP in patients with acromegalic relatives or the menin gene in patients
with multiple endocrine neoplasia type 1 (MEN1). If you have relatives with pituitary tumors
or other endocrine disorders, be sure to tell your doctor, so he can try to identify genetic
alterations and comment on the results, as well as search on other members of your family
early presence of the disease.

4. MAGNETIC RESONANCE OF THE BRAIN FOCUSED ON THE PITUITARY
WITH GADOLINIUM
When the elevation of IGF-1 is confirmed and GH is not suppressed during the oral glucose
tolerance test, the next step is to perform an MRI focused on the pituitary gland. Thus, it will
be possible to assess whether one is in the presence of a microadenoma or a macroadenoma.
This study is fundamental since it certifies the diagnosis and also allows evaluating whether
the adenoma is invading the structures that surround it (for example, the cavernous sinus) or
whether it has a significant suprasellar extension. These factors are of vital importance to
know the degree of response to eventual surgery.
Very rarely (less than 2%), MRI may not show a pituitary adenoma. These cases are defined
as extrapituitary causes of acromegaly or gigantism and require other types of
complementary studies.
COMPUTERIZED FIELD OF VISION
In the case of macroadenomas, it is necessary to determine if there is any compromise in the
optic pathway (optic chiasm, optic nerves, optic tract). The typical picture of visual field loss
is known as bitemporal hemianopsia and is produced by compression of the optic chiasm by
the macroadenoma. Bitemporal hemianopsia is characterized by a lack of the most lateral
peripheral vision in both eyes and patients can only see what is directly in front of them.
There may be other types of visual deficits ranging from quadrantopia to amaurosis
(blindness).