Thyroid nodules are thyroid lumps found in
approximately 5% of the population at palpation screening, and
is almost 7 to 8-fold more frequent at ultrasonic screening.
Thyroid nodules are rare in children and adolescents and
increase almost linearly with age; females are affected 2 to 4
times more frequently than males. Nodular thyroid disease is a
heterogenous disorder with regard to clinical, functional or
histological aspects: nodules may be single or multiple, hyper-
or hypo-functioning, benign or malignant. Malignant nodules
account for roughly 10% of all nodules. The large majority of
these arises from the follicular epithelium and includes
well-differentiated carcinomas in 75% of cases and poorly
differentiated or anaplastic in 15% of cases. Medullary cancer
arising from calcitonin-producing parafollicular cells account
for approximately 10% of cases.
about thyroid nodules
Simply put, thyroid nodules are lumps which commonly arise
within an otherwise normal thyroid gland. Often these abnormal
growths of thyroid tissue are located at the edge of the thyroid
gland so they can be felt as a lump in the throat. When they are
large or when they occur in very thin individuals, they can even
sometimes be seen as a lump in the front of the neck. The
following is a list of facts regarding thyroid nodules:
- One in 12 to 15 women has a thyroid nodule
- One in 40 to 50 men has a thyroid nodule
- More than 90 percent of all thyroid nodules are benign
- Some are actually cysts which are filled with fluid rather
than thyroid tissue
- Is the nodule one of the few that are cancerous?
- Is the nodule causing trouble by pressing on other
structures in the neck?
- Is the nodule making too much thyroid hormone?
These questions can be answered after your endocrinologist
performs some tests. These include blood tests for thyroid
activity, an ultrasound scan to study the nodule, and a biopsy.
Early diagnosis and treatment is important
to reduce thyroid cancer mortality. However since malignant
nodules are a small minority, to directly operate on all nodules
is impractical, cost-ineffective and would expose people with
benign nodules to unnecessary risks.
Fine needle aspiration biopsy (FNAB), also called fine needle
aspiration cytology (FNAC), of the thyroid was first described
in 1948. It gained widespread use since the 1970s, and is an
accurate and useful diagnostic procedure for distinguishing
benign from malignant thyroid nodules. The routine use of FNAB
has allowed doctors to spare patients from unnecessary
operations for benign nodules and reduce costs of care.
FNAB is usually carried out in an outpatient setting. It is
virtually painless and free of major complications. The patient
lies on a couch with a pillow under the neck to relax the neck
muscles. The nodule is identified by palpation or ultrasound. A
very fine needle is inserted and then moved back and forth to
obtain thyroid material. Local anaesthesia is given prior to
biopsy. To increase cellular yield it may be necessary to
perform 3 to 5 aspirations. The material is then smeared onto
glass slides and stained with special dyes. The slides are then
examined under a microscope. A cytopathologist (specialist in
studying cells for cancerous features) will do a careful study
of the slides. Results are usually available in 1 to 2 work
days. After the FNAC, the patient will be allowed to go home.
The whole procedure usually takes no more than 30 minutes. Most
patients do not experience any problems after the biopsy. A few
minority may experience some soreness and bruising in the
thyroid area. Analgesic medication will be given and if
necessary, medical leave.
If the nodule is not cancerous and is not
causing any symptoms, it may be left alone. Surgery is not
necessary. Benign nodules do not turn into malignant ones over
If thyroid cancer is indeed discovered, you need
to be treated. There are over 11,000 new cases of thyroid cancer
each year in the United States. Females are more likely to have
thyroid cancer at a ratio of three to one. Thyroid cancer can
occur in any age group, although it is most common after age 40,
and its aggressiveness increases significantly in older
patients. The majority of patients present with a nodule on
their thyroid which typically does not cause symptoms.
thyroid cancers are very curable. In fact, the most common types
of thyroid cancer (papillary and follicular) are the most
curable. In younger patients, both papillary and follicular
cancers can be expected to have better than 95% cure rate if
treated appropriately. Both papillary and follicular cancers are
typically treated with complete removal of the lobe of the
thyroid which harbors the cancer, PLUS, removal of most or all
of the other side.
cancer of the thyroid is significantly less common, but has a
worse prognosis. Medullary cancers tend to spread to large
numbers of lymph nodes very early on, and therefore requires a
much more aggressive operation than does the more localized
cancers such as papillary and follicular. This cancer requires
complete thyroid removal PLUS a dissection to remove the lymph
nodes of the front and sides of the neck.
least common type of thyroid cancer is anaplastic which has a
very poor prognosis. It tends to be found after it has spread
and is not cured in most cases. Often an operation cannot remove
all the tumor.
cancer is unique among cancers, in fact, thyroid cells are
unique among all cells of the human body. They are the only
cells which have the ability to absorb iodine. Iodine is
required for thyroid cells to produce thyroid hormone, so they
absorb it out of the bloodstream and concentrate it inside the
cell. Most thyroid cancer cells retain this ability to absorb
and concentrate iodine. This provides a perfect "chemotherapy"
strategy. Radioactive iodine is given to the patient and the
thyroid will absorb and concentrate it. Since all other cells of
our bodies cannot absorb the toxic iodine, they are unharmed.
The thyroid cancer cells, however, will concentrate the poison
within themselves and the radioactivity destroys the cell from
within. No sickness. No hair loss. No nausea. No diarrhea. No
all patients with thyroid cancer need radioactive iodine
treatments after their surgery. This is important to know.
Others, however, should have it if a cure is to be expected.
Your endocrinologist will advise you about what treatment is
best for you. Following treatment you need to taking thyroid
hormone and maintain followup for life.