THYROID GLAND
DISEASE
Diseases of thyroid gland.
Endemic, sporadic goiters.
Thyrotoxicosis. Thyroidites.
Reader: Kostiv S. Ya.
Palpation of
the thyroid
gland
(isthmus)
Palpation of
the thyroid
gland (right
lobe)
Palpation of
the thyroid
gland (left
lobe)
Palpation of the thyroid gland
Palpation of the thyroid gland
CLASSIFICATION OF THE GOITER
ACCORDING TO THE FORM OF
ENLARGMENT
• Diffuse goiter;
• Nodular goiter;
• Mixed goiter.
The degree of enlargement
• 0 – the thyroid gland is not palpated;
• І – the isthmus of the gland is noticeable during
swallowing and could be palpated;
• ІІ – entire gland is noticeable during swallowing and
could be palpated;
• ІІІ – the enlargement of gland results in evident
thickening of neck (“a thick neck”);
• ІV – the gland considerably enlarged and sharply
deforms neck;
• V – the enlargement reaches excessive size (goiter of
major sizes).
CLASSIFICATION OF THE GOITER
ACCORDING TO THE FUNCTIONAL
STATE
• Euthyroid goiter (normal function);
• Hyperthyroid (excessive function);
• Hypothyroid (reduced function).
CLASSIFICATION OF THE GOITER
ACCORDING TO THE
LOCALIZATION
• Typical localization (anterior surface of the
neck);
• Retrosternal goiter;
• Ectopic goiter (goiter of the base of tongue,
intrathoracic goiter);
• Goiter of the additional glands;
• Presternal goiter.
The nodular goiter of the III degree
The nodular
goiter of the
IV degree
Goiter of major sizes
The goiter
formation
(intrathoracic
goiter)
Presternal goiter
Clinical manifestations of
hyperthyroidism
Symptoms of hyperthyroidism include weight
loss during normal or increased appetite,
heat intolerance, excessive perspiration,
muscle weakness, oligomenorrhea. Signs of
hyperthyroidism include goiter, sinus
tachycardia or atrial fibrillation, tremor,
hyperreflexia, fine or thinning hair, muscle
wasting.
Clinical features of
hypothyroidism
include cold intolerance, weight gain,
constipation, edema (especially of the
eyelids, hands, and feet), dry skin, weakness,
somnolence, and menorrhagia.
Biochemical thyroid function
testing
Currently, measurement of serum TSH level
and free T4 (FT4) is the best and most
efficient combination of blood tests for
diagnosis of most patients with thyroid
disorders.
Biochemical thyroid function
testing
Measurement of TSH (0.3-5.0 mIU/L) by a secondgeneration sensitive TSH (sTSH) test is the single
most useful biochemical test in the diagnosis of
thyroid illness. In most ambulatory and
hospitalized patients without pituitary disease,
increased sTSH signifies hypothyroidism,
suppressed sTSH suggests hyperthyroidism, and
normal sTSH reflects a euthyroid state.
Biochemical thyroid function
testing
Measurement of T3 (80-200 ng/dL) is test in
hypothyroidism. This test is useful in the
occasional patient with suspected
hyperthyroidism, suppressed sTSH.
Biochemical thyroid function
testing
Antithyroid microsomal antibodies are found in
the serum of patients with autoimmune thyroiditis
(Hashimoto's thyroiditis), and measurement of
these antibodies is helpful to diagnose this
common cause of hypothyroidism. Anti-TSH
receptor antibodies, which stimulate the TSH
receptor, are detectable in more than 90% of
patients with autoimmune hyperthyroidism
(Graves' disease); however, their measurement is
not often needed in the diagnosis of this disease.
Thyroid Function Test
Algorithm
A useful thyroid function test algorithm (Clin Lab
Med 13:673, 1993) includes sTSH assay as the
initial test. If this is normal, no further tests are
needed. If sTSH is elevated, FT4I and microsomal
antibodies are measured to confirm
hypothyroidism, which is often autoimmune. If
sTSH is suppressed, FT4I is measured to confirm
primary hyperthyroidism. If TSH is low and FT4I
is normal, T3 is measured to diagnose T3
thyrotoxicosis.
Scaning of the thyroid gland
Scaning of the thyroid gland
Thyroid imaging is most often accomplished
with radionuclide scanning or ultrasound;
other imaging modes, including computed
tomographic (CT) scanning and MR scan,
are useful in special circumstances.
Technetium thyroid scanning
Technetium thyroid scanning 20 minutes after the intravenous
injection of technetium-99m (99mTc) is useful in determining the
size of the thyroid and in differentiating solitary functioning
nodules from multinodular goiter or Graves' disease.
Hypofunctioning areas (cyst, neoplasm, or suppressed tissue
adjacent to autonomous nodules) are "cold," areas of increased
synthesis are "hot." "Cold" nodules have a 15-20% risk of
malignancy; most should be removed. "Hot" nodules are almost
never malignant. 99mTc thyroid scans are most useful as adjunctive
tests to assess risk of malignancy in patients with indeterminate
thyroid nodule cytology or in hyperthyroid patients suspected of
having a hyperfunctioning thyroid adenoma. Thyroid scanning 4-24
hours after oral iodine-131 (131I) is useful to identify metastatic
differentiated thyroid tumors and to both confirm a diagnosis of
Graves' disease.
Radionuclide thyroid scans of
normal thyroid gland
Radionuclide thyroid scans of
thyroid gland (goiter)
Radionuclide thyroid scans of
thyroid gland (diffuse goiter)
Radionuclide thyroid scans of
thyroid gland (diffuse goiter)
Radionuclide thyroid scans of
thyroid gland (nodular goiter)
Thyroid ultrasonography with
high-frequency (7.5-10.0 MHz)
Thyroid ultrasonography with high-frequency
(7.5-10.0 MHz) determines gland volume as well
as the number and character of thyroid nodules.
Although not completely reliable, features
suggestive of malignancy on ultrasound include
hypoechoic pattern, irregular margins, and
microcalcifications. Ultrasound is useful to guide
fine-needle aspiration (FNA) biopsy and cyst
aspiration. Cysts seen on ultrasound, especially
those larger than 3 cm, are malignant in up to 14%
of cases.
Nodular goiter
Cyst of the thyroid gland
Punction of the cyst of the thyroid gland
X-Ray examination, CT scanning
and MR scan
X-Ray examination, CT scanning and MR
scan of the thyroid are costly and generally
are reserved for assessing substernal or
retrosternal masses suspected to be goiters.
Retrosternal goiter
Retrosternal
goiter
(X-Ray and CT)
Retrosternal goiter
Retrosternal goiter
Retrosternal goiter
Retrosternal
goiter
Retrosternal goiter
(electro X-Ray)
Retrosternal goiter
Termogram of the goiter.
Trachea deformation
Complication of the goiter
(tracheomalatia )
Autoimmune diffuse toxic goiter
(Graves' disease)
Autoimmune diffuse toxic goiter (Graves'
disease) is the most common cause of
hyperthyroidism and may be caused by
stimulating immunoglobulins directed
against the TSH receptor. Graves' disease
may be treated with antithyroid drugs,
ablation with radioactive iodine (RAI), or
surgery, depending on the clinical situation.
Diffuse goiter
Diffuse goiter
Diffuse goiter
Diffuse goiter
(Pathological
exophthalm)
Pathological exophthalm
Pathological
exophthalm
External signs of the thyroid gland
diseases
Treatment of the Graves' Disease
Thionamide drugs, such as propylthiouracil (PTU)
or methimazole, are the initial therapy in most
cases. PTU (100-300 mg p.o. t.i.d.) is given for 46 weeks until the patient becomes euthyroid; then
the dosage usually is decreased (PTU, 100 mg p.o.
t.i.d.). The patient is then treated empirically for 618 months, at which time the drugs are withdrawn.
Clinical features that favor remission include small
gland size and mild hyperthyroidism of recent
onset, although overall, long-term remission is
achieved in less than 20-30% of patients.
Treatment of the Graves' Disease
Antithyroid drugs also are used to prepare
thyrotoxic patients for surgery or ablative
therapy. PTU may be given during
pregnancy at reduced doses, especially if
thyroidectomy is necessary in the second
trimester. Minor adverse reactions occur
infrequently and include rash, hepatitis,
arthralgias, and a lupuslike syndrome.
Agranulocytosis is a rare (0.5%) but serious
side effect of thionamide therapy.
Treatment of the Graves' Disease
Ablation with RAI is the treatment of choice for
most patients with Graves' disease. A dose of 510 mCi of 131I is given orally and is 75% effective
after 4-12 weeks. In the 25% of patients with
persistent thyrotoxicosis after 12 weeks, double
the initial dose is repeated. After treatment, there is
a high incidence (70%) of eventual permanent
hypothyroidism, which is managed easily by
replacement therapy. There are virtually no other
long-term side effects of RAI (i.e., no significantly
increased risk of thyroid cancer, leukemia, or
teratogenicity).
Treatment of the Graves' Disease
Ablation with RAI is the treatment of choice
for most patients with Graves' disease.
Contraindications to radiotherapy include
pregnant women, newborns, patients who
refuse, or patients with low RAI uptake
(<20%) in the thyroid. Treatment of children
or young adults (younger than 30 years) with
RAI is controversial because of presumed
long-term oncogenic risks.
Thyroidectomy for Graves' disease
Thyroidectomy for Graves' disease may be
indicated for children or, patients unresponsive to
medical therapy, or patients who refuse RAI.
A bilateral subtotal thyroidectomy should be
performed with the goal of leaving a 1- to 2-g
vascularized cuff of thyroid on each side.
However, some centers advocate total
thyroidectomy as primary treatment to decrease
recurrence rate of goitrous disease. Risks of
surgery are extremely small (<1%) in experienced
hands but include hypoparathyroidism and injury
to the recurrent laryngeal nerve.
Subtotal subfascial resection
of the thyroid gland
Operation. Retrosternal goiter.
Resection of the thyroid gland
Operation right-side hemithyroidectomy
Subtotal subfascial resection of the
thyroid gland
Thyroidectomy for Graves' disease
Surgery results in hypothyroidism less
frequently than does RAI (N Engl J Med
311:426, 1984). The long-term incidence of
recurrent hyperthyroidism after surgery is
approximately 10%. Patients with recurrent
hyperthyroidism after thyroidectomy should
be treated with RAI.
Management of complications after
thyroidectomy
Hemorrhage is a rare but serious
complication of thyroidectomy that usually
occurs within 6 hours of surgery.
Management can require control of the
airway by endotracheal intubation and can
rarely mandate urgent opening of incision
and evacuation of hematoma before
returning to the operating room for wound
irrigation and ligation of the bleeding point.
Management of complications after
thyroidectomy
Transient hypocalcemia commonly occurs 24-48 hours after
thyroidectomy but infrequently requires treatment. Patients
who are markedly symptomatic or who have serum calcium
below 7 mg/dL are given 1-2 ampules (10-20 mL) of 10%
calcium gluconate i.v. over 1-2 minutes followed by
temporary oral calcium carbonate (500 mg p.o. t.i.d.). More
prolonged intravenous replacement is achieved by mixing 6
ampules of 10% calcium gluconate (540 mg elemental
calcium) in D5W, 500 mL, for infusion at 1 mL/kg per hour.
Permanent hypoparathyroidism is uncommon after total
thyroidectomy. Normal parathyroid tissue removed or
devascularized at the time of total thyroidectomy may be
autotransplanted into sternocleidomastoid muscle to prevent
postoperative hypocalcemia
Management of complications after
thyroidectomy
Recurrent laryngeal nerve (RLN) injury is a devastating
complication of thyroidectomy that should occur rarely
(<1%). Unilateral RLN injury causes hoarseness, and
bilateral injury compromises the airway, necessitating
tracheostomy. Repeat neck exploration, thyroidectomy for
extensive goiter or Graves' disease, and thyroidectomy for
fixed, locally invasive cancers are procedures particularly
prone to RLN injury. Intentional (as with locally invasive
cancer) or inadvertent transection of the RLN can be
repaired primarily or with a nerve graft, although the
efficacy of these repairs is not known. Temporary RLN
palsies can occur during thyroidectomy, and these usually
resolve over a period of 4-6 weeks.
Management of complications after
thyroidectomy
Recurrent laryngeal nerve (RLN) injury
The external branch of the superior laryngeal
nerve may be injured if not identified during
ligation of the superior thyroid pole vascular
bundle. This injury results in weakness of the
patient's voice at high pitch. The best
prevention of these injuries is a thorough
understanding of the anatomy of these nerves.