Pituitary
Tumors
The pituitary gland, also
known as hypophysis,is
a small
endocrine oval gland located inside of human head,
at the base of the brain, which weights about
0.5
grams.
Being a part of the endocrine system, it works in making and releasing hormones into the blood to regulate metabolism, growth and
development, tissue function, sexual function, reproduction, sleep, mood, metabolism,
hunger, and
others. The pituitary
gland produces hormones that run most of the
activity of other endocrine glands in the body by
indicating them to produce and release different
hormones.
Pituitary tumors normally originate
in the cells of the pituitary gland. They can be non-cancerous
(adenoma
or benign) or cancerous;
although they usually act benign tumors:
-
Pituitary
adenomas and craniopharyngiomas, which secrete too
much of certain hormones.
-
Chromophobe adenomas (adenomas of the
chromophobe cells of the anterior pituitary
gland),
which are also pituitary adenomas (non-cancerous), but cause
the pituitary gland to secrete not enough of certain hormones.
In
other cases, the tumor may degenerate. At the origin
of the tumor, an abnormal cell, called “CrookeCell “which comes from the degeneration of normal cells of the pituitary gland, causing a type of pituitary cancer; it can be a local or advanced cancer. When a
pituitary cancer spreads into nearby tissues or other parts of the body (metastasize), it is considered as a serious
or metastasized cancer.
Causes of Pituitary Tumors
The cells of the pituitary gland sometimes undergo
changes that make their way of growth
or behavior abnormal. These changes can lead to the formation of non-cancerous
tumors such as pituitary adenomas, or cancerous tumor
(cancer). The good news is over 99% of pituitary
tumors are non-cancerous, although they can cause
serious health problems in the patient. For instance, some tumors cause vision problems and head ache due to
their location in the brain. Most pituitary tumors produce pituitary
hormones, and generate different disorders as they release hormones.
In rare cases, changes in
the pituitary cells can
cause cancer. This is called pituitary carcinoma (or just pituitary cancer). Scientists do not know
to this day, the reasons for the development of tumor
from the pituitary gland, but
these risks below are suspected:
Multiple Endocrine Neoplasia
(MEN) – MEN
consists of a group of inherited or genetic
syndromes, that
affect the endocrine system. There are several types
of multiple endocrine
neoplasia; each one has a different genetic mutation or an abnormal
characteristic pattern in a gene. They can
be cancer (carcinoma) or benign (adenoma).
Carney Complex –
this hereditary
conditionis a very
rare genetic
disorder that increases the risk of developing several types of tumors, such as pituitary
tumors, adrenal tumors and other endocrine tumors. It
can also increase the risk of the non-cancerous
tumors called myxomas of the heart and skin, which is characterized by spotty skin
pigmentation on lips, inner
and outer corners of the eyes, the membrane lining (conjunctiva) of the eye, and around the genital
area.
Familial Isolated
Pituitary Adenoma(FIPA)- FIPA is an inherited disorder that increases the
risk of suffering from non-cancerous pituitary tumors. IFAP is caused by a mutation of the AIP gene which produces a protein involved in
the control of cell growth.
AIP gene mutation leads to growth outside control of
pituitary gland cells which then
forms a tumor.
McCune-Albright Syndrome – this is a rare disorder
that
affects the bones, skin, and several hormone-producing (endocrine) tissues
.
People with McCune-Albright syndrome develop areas of abnormal scar-like (fibrous) tissue in their bones, a
condition called polyostotic fibrous dysplasia.
Individuals
with this disorder are at increased risk
of having pituitary tumor.
Pituitary Tumor Symptoms and Treatment
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