Hashimoto's thyroiditis or chronic lymphocytic thyroiditis is an
autoimmune disease in which the thyroid gland is attacked by a variety of
cell- and antibody-mediated immune processes. It was the first disease to
be recognized as an autoimmune disease. It was first described by the
Japanese specialist Hakaru Hashimoto in Germany in 1912.
Signs and symptoms:
Hashimoto's thyroiditis very often results in hypothyroidism with bouts of
hyperthyroidism. Symptoms of Hashimoto's thyroiditis include weight gain,
depression, mania, sensitivity to heat and cold, paresthesia, chronic fatigue,
panic, bradycardia, tachycardia, congestive heart failure, high cholesterol,
reactive hypoglycemia, constipation, migraines, muscle weakness, joint
stiffness, menorrhagia, myxedematous psychosis, cramps, memory loss,
vision problems, infertility and hair loss.
Enlargement of the thyroid is due to lymphocytic infiltration and fibrosis
rather than tissue hypertrophy. Physiologically, antibodies against thyroid
peroxidase (TPO) and/or thyroglobulin cause gradual destruction of follicles
in the thyroid gland. Accordingly, the disease can be detected clinically by
looking for these antibodies in the blood. It is also characterized by invasion
of the thyroid tissue by leukocytes, mainly T-lymphocytes.
Hashimoto's thyroiditis. Transverse gray-scale ultrasound (a) and color Doppler
(b) neck, of a 35-year-old female patient, who presented with features of
hypothyroidism and had antithyroid antibodies positive for the disease,
demonstrates diffuse enlargement of thyroid gland with linear echogenic fibrous
bands (arrowheads) but normal vascularity. Note a small hypoechoic lymph node
(arrow) in posterior aspect of inferior pole of left lobe of the thyroid gland.
Diffuse Hashimoto's thyroiditis who presented with features of
hypothyroidism and had anti-thyroid antibodies positive for the disease.
Transverse gray-scale ultrasound neck (a) demonstrates diffuse enlargement
of thyroid gland with heterogeneous echotexture. Multiple tiny and discrete
hypoechoic nodules (micronodules, arrows) and few linear echogenic septae
(arrowhead) are also noted. Color Doppler sonogram (b) demonstrates mildly
increased parenchymal vascularity.
Acute infectious thyroiditis (AIT) also known as
suppurative thyroiditis, microbial inflammatory
thyroiditis, pyogenic thyroiditis and bacterial
The thyroid is normally very resistant to infection. Due
to a relatively high amount of iodine in the tissue, as
well as high vascularity and lymphatic drainage to the
region, it is difficult for pathogens to infect the thyroid
tissue. Despite all this, a persistent fistula from the
piriform sinus may make the left lobe of the thyroid
susceptible to infection and abscess formation. AIT is
most often caused by a bacterial infection but can also
be caused by a fungal or parasitic infection, most
commonly in an Immumocompromised host.
2 cases with acute suppurative thyroiditis. Contrast-enhanced CT
shows a fluid collection (arrows) with internal gas (arrowhead)
involving lobes of thyroid gland (open arrows) and adjacent soft tissue.
Axial CT image with contrast enhancement at the level of the
thyroid gland shows an abscess (A) with an air-fluid level
anterior to the trachea and multiple abscess of the left images.
Silent thyroiditis is swelling (inflammation) of the thyroid
gland, in which the person alternates between
hyperthyroidism and hypothyroidism.
Subacute granulomatous thyroiditis (De Quervain,s)
is an uncommon disease that occurs most often in
women in their second to fifth decades of life. This
disease usually presents with thyroid tenderness, a low
grade fever, and occasional dysphagia. The disease
resolves spontaneously, usually without thyroid function
abnormalities. We herein present the CT and MR
imaging findings of two cases of subacute
Subacute granulomatous thyroiditis (nonsuppurative
thyroiditis, subacute thyroiditis, or de Quervain
thyroiditis) is a self-limited inflammatory disease of the
thyroid gland that most often occurs secondary to a viral
Subacute thyroiditis with enlargement of the left thyroid lobe with no uptake
with the thyroid lobe. Decreased attenuation can be seen in the posterior
portion of the left thyroid lobe with increased intensity at MRI images.
The transverse right (A) and left (B), and longitudinal right (C) and left (D) thyroid sonograms
show ill-defined hypoechoic lesions involving nearly the entire area of both thyroid glands.
Both thyroids are diffusely enlarged, but no cervical lymphadenopathy was detected.
Subacute granulomatous thyroiditis was confirmed by fine needle aspiration biopsy
The transverse (A) and longitudinal (B) sonograms of the right thyroid reveal an
ill-defined elongated hypoechoic lesion, which is a typical finding of subacute
thyroiditis. Color Doppler ultrasonography (C) shows no vascular flow in the
hypoechoic lesion. Cytology suggests subacute granulomatous thyroiditis (D). On
the day after steroid therapy, the patient felt free of neck pain. On sonogram
after two months (E, F), the size of the hypoechoic area was markedly decreased.
Euthyroid sick syndrome is low serum levels of thyroid hormones in
clinically euthyroid patients with nonthyroidal systemic illness.
Diagnosis is based on excluding hypothyroidism. Treatment is of the
underlying illness; thyroid hormone replacement is not indicated.
Thyroid nuclear scan of a patient with a euthyroid goiter showing different
projections with thyroid enlargement and retro-sternal extension.
Hyperthyroidism is a condition in which the thyroid gland is
overactive and makes excessive amounts of thyroid hormone. The
thyroid gland is an organ located in the front of your neck and releases
hormones that control your metabolism (the way your body uses
energy), breathing, heart rate, nervous system, weight, body
temperature, and many other functions in the body. When the thyroid
gland is overactive (hyperthyroidism) the body’s processes speed up
and you may experience nervousness, anxiety, rapid heartbeat, hand
tremor, excessive sweating, weight loss, and sleep problems, among
The symptoms of hyperthyroidism include the following:
Fatigue or muscle weakness, Hand tremors, Mood swings,
Nervousness or anxiety, Rapid heartbeat, Heart palpitations or
irregular heartbeat, Skin dryness, Trouble sleeping, Weight loss,
Increased frequency of bowel movements, Light periods or skipping
Some people may develop a goiter, which is an enlarged thyroid gland
that feels like a swelling in the front of your neck.
Causes of hyperthyroidism:
The most common cause of hyperthyroidism is the autoimmune
disorder Graves’ disease. In this disorder, the body makes an antibody
(a protein produced by the body to protect against a virus or bacteria)
called thyroid-stimulating immunoglobulin (TSI) that causes the thyroid
gland to make too much thyroid hormone. Graves’ disease runs in
families and is more commonly found in women.
Hyperthyroidism also may be caused by a toxic nodular or multinodular
goiter, which are lumps or nodules in the thyroid gland that cause the
thyroid to produce excessive amounts of thyroid hormones. In addition,
inflammation of the thyroid gland—called thyroiditis—resulting from a
virus or a problem with the immune system may temporarily cause
symptoms of hyperthyroidism. Furthermore, some people who
consume too much iodine (either from foods or supplements) or who
take medications containing iodine (such as amiodarone) may cause
the thyroid gland to overproduce thyroid hormones.
Finally, some women may develop hyperthyroidism during pregnancy
or in the first year after giving birth.
Graves′ disease, the thyroid usually appears moderately
enlarged with hypoechoic area inside.
Goiter (GOI-tur) is an abnormal enlargement of your thyroid
gland. Although goiters are usually painless, a large goiter can
cause a cough and make it difficult for you to swallow or breathe.
The most common cause of goiter worldwide is a lack of iodine in
the diet. In the United States, where the use of iodized salt is
common, a goiter is more often due to the over- or
underproduction of thyroid hormones or to nodules that develop
in the gland itself.
A visible swelling at the base of your neck that may be
particularly obvious when you shave or put on makeup
A tight feeling in your throat.
Multinodular goiter. A. Transverse dual ultrasound image shows enlargement of thyroid
lobes and isthmus and multiple hyperechoic solid nodules with uniform thin halo (arrows).
Mixed solid and cystic thyroid nodule in the left lobe. Tr: tracheal gas shadow. B.
Transverse sonogram and color-doppler mode scan show a well-defined isoechoic thyroid
nodule with thin complete hypoechoic halo, intranodular cystic/colloid space and
peripheral vascularity, findings indicative of a hyperplasic nodule.
A lingual thyroid is a specific type of ectopic thyroid, and results from lack of
normal caudal migration of the thyroid gland.
Ultrasound: Ultrasound is only of use in demonstrating absent thyroid tissue in
the normal location, which is the case in the majority of cases. Only occasionally
do patients have thyroid tissue both at the tongue base and elsewhere in the
CT: CT demonstrates are hyperdense soft tissue mass, of the same attenuation as
normal thyroid tissue. It is hyperdense on account of the accumulation of iodine
within the gland. Following contrast administration, the entire gland
demonstrates prominent homogenous enhancement (again just like the normal
thyroid gland). There are occasional case reports of inhomogeneous contrast
MRI: Usually seen as a well defined mass with no invasive features
Signal characteristics include : T1 - iso to hyperintense to muscle
T2 - can vary from hypo to iso to hyperintense to muscle .
T1 C+ (Gd) - homogeneous contrast enhancement
Nuclear medicine: A thyroid scan is excellent at not only confirming the
diagnosis, but also identifying the presence of any thyroid tissue elsewhere in
Thyroglossal duct cysts are the most common congenital neck cyst. They are typically
located in the midline and are the most common midline neck massses in young
Ultrasound: Unless infected, they are painless, fluctuant masses which spread the
strap muscles. The fluid is usually anechoic and the walls are thin, without internal
However, in some cases, the internal fluid may contain debris. This is particularly the
case in the adult patient where the cysts may be complex heterogeneous masses.
If there is associated infection, there may be surrounding inflammatory change.
CT: At CT, thyroglossal duct cysts are thin walled, smooth, well defined homogeneously
attenuating lesions with an anterior midline or para-midline location. The generally
accepted rule is that they should be within 2 cms of the midline. The may demonstrate
slight rim (capsular) enhancement.
Sternocleidomastoid is typically displaced posteriorly or posterolaterally and in some
cases, they may be embedded in the infrahyoid strap muscles.
MRI : T1: variable low signal: if low protein / uncomplicated
high signal (most common ) due to previous hemorrhage / infection
high protein (probably due to previous complication)
T2 - typically high signal
T1 C+ (Gd)
no enhancement in uncomplicated cysts
thin peripheral enhancement may be seen
Thyroid nodules are lumps which commonly arise within an otherwise normal
thyroid gland. They indicate a thyroid neoplasm, but only a small percentage of
these are thyroid cancers.
5% of adults have thyroid nodules, with a 5:1 female :male ratio.
95% of thyroid nodules are benign.
There are different types of thyroid nodules.
Colloid nodules. These are one or more overgrowths of normal thyroid tissue.
These growths are not cancerous (benign), may grow large, but do not spread
beyond the thyroid gland.
Thyroid cysts. These are fluid-filled or partially solid/partially fluid-filled growths
inside the thyroid gland.
Inflammatory nodules. These nodules develop as a result of chronic inflammation
of the thyroid gland. These growths may or may not cause pain.
Multinodular goiter. Sometimes an enlarged thyroid (goiter) is composed of many,
usually benign, nodules.
Hyperfunctioning thyroid nodules. These nodules produce thyroid hormone, which
may lead to the development of hyperthyroidism. Hyperthyroidism can affect the
heart, leading to such complication as sudden cardiac arrest, hypertension,
arrhythmias; as well as osteoporosis and other health problems.
Thyroid cancer. Of the nodules that can form as the thyroid gland enlarges,
fortunately, less than 5 percent are cancerous.
Transverse ultrasound scan shows a well-defined, homogeneous, solid iso-
hypoechoic oval-shaped thyroid nodule, suggestive of a follicular lesion. B.
Transverse color-Doppler scan demonstrates intranodular and peripheral vascularity.
Multinodular goitre. A. Transverse dual ultrasound image shows enlargament of thyroid
lobes and isthmus and multiple hyperechoic solid nodules with uniform thin halo
(arrows). Mixed solid and cystic thyroid nodule in the left lobe. Tr: tracheal gas shadow.
B. Transverse sonogram and color-doppler mode scan show a well-defined isoechoic
thyroid nodule with thin complete hypoechoic halo, intranodular cystic/colloid space and
peripheral vascularity, findings indicative of a hyperplastic nodule.
Spongiform nodule. A. Transverse and B. longitudinal ultrasound scan shows a thyroid
nodule with multiple cystic spaces and punctuated echogenic foci with comet tail artifact.
C. Transverse and D. longitudinal color-doppler mode scan shows peripheral vascularity.
Radioactive nuclear medicine study showing a 'hot'
thyroid nodule in a patient with hyperthyroidism.
Follicular adenoma: Shows high signal and intense
enhancement relative to the thyroid tissue.
Thyroid cancers can be classified according to their histopathologically
.characteristics. The following variants can be distinguished
(distribution over various subtypes may show regional variation):
Papillary thyroid cancer .(75% to 85% of cases) – often in young
females – excellent prognosis. May occur in women with familial
adenomatous polyposis .and in patients with Cowden syndrome.
Follicular thyroid cancer (10% to 20% of cases); occasionally seen in
patients with Cowden syndrome.
Medullary thyroid cancer (5% to 8% of cases)- cancer of the
parafollicular cells, often part of multiple endocrine neoplasia type 2.
Poorly differentiated thyroid cancer
Anaplastic thyroid cancer (Less than 5%). It is not responsive to
treatment and can cause pressure symptoms.
Squamous cell thyroid carcinoma.
Sarcoma of thyroid.
Ultrasound of a papillary carcinoma (a) small hypoechoic
solid nodule with punctate calcification (arrows), (b)
predominantly cystic nodule (arrow heads) with smaller
solid component with punctate calcification (arrows).
Ultrasound of solid hypoechoic
follicular thyroid cancer
Two cases of Papillary carcinoma with lymph node metastasis.
Multifocal papillary carcinoma with multi-nodular masses showing
marked enhancement, Extra-thyroidal extension is present
bilaterally. Bilateral LN, metastasis show marked enhancement.
Anaplastic thyroid tumor. Axial unenhanced and contrast-enhanced CT scan images
through the lower neck. Unenhanced images show an heterogeneous tissue replacing
and expanding the thyroid gland, with some foci of calcifications inside. After contrast
injection, the lesion enhances at the periphery, and the center remains
hypoattenuating, suggesting necrosis. The mass has displaced the larynx to the left,
invaded it and partly destroyed its cartilage. All these imaging findings provide
evidence of the aggressive nature of this anaplastic thyroid carcinoma.
Anaplastic carcinoma , Esophagram demonstrates focal extrinsic
narrowing of the upper esophagus, MRI large heterogenous mass lesion,
invade the trachea and displacing the esophagus to the right side.
Anaplastic carcinoma, patient with hoarseness and dysphagia, MRI
large infiltrative mass lesion, extending directly to the right vocal
cord, with extension to the post-cricoid space.
Primary medullary thyroid carcinoma, the tumour appears iso-intense
relative to the gland with marked enhancement at the post-contrast study.
Medullary carcinoma, show round well marginated mass, iso-intense
at the T1WI and bright at the T2WI and mild enhancement.
US and CT Scan show mass lesion over left thyroid
gland, proved to be primary lymphoma.
Thyroid lymphoma. Axial contrast-enhanced CT image shows diffuse enlargement of
the thyroid gland by a relatively homogenous mass causing tracheal and jugular vein
compression. Thyroid lymphoma may presents as a focal mass, multiple thyroid
nodules, or diffuse enlargement of the gland, with rapid growth. An absence of
calcification and necrosis aids in distinguishing it from anaplastic carcinoma. It also
shows a propensity to encircle the trachea, sometimes producing a characteristic
‘‘doughnut sign’’ on CT. Associated cervical adenopathy is also present in this patient.
Diffuse large B-cell lymphoma of the thyroid gland in a 73-year-old man with Sjögren’s
syndrome. (a, b) Contrast-enhanced CT images show a huge tumor replacing the left
thyroid lobe (yellow arrows). Cervical lymphadenopathy is also visualized (green arrow).
Note fatty deposition in the left parotid gland (blue arrow). (c) FDG-PET/CT fused image
shows intense FDG uptake in the tumor and lymph nodes. (d) T2WI demonstrates relatively
homogenous signal intensity of the tumor for its size. (e) Diffusion-weighted image
visualizes the tumor and enlarged lymph node (orange arrow) of hyperintensity.
Axial computed tomography (CT) scan showed a large low attenuation synovial sarcoma
replacing the thyroid gland with possible invasion to the trachea. (B) Axial CT scan
performed 2 weeks after the first CT scan revealed tracheal intraluminal invasion. (C) Chest
CT scan showed multiple variable sized nodular lesions suggestive of lung metastasis.
Two cases of primary Synovial Sarcoma of the Thyroid Gland.
CASTLE neoplasm with a hypoechoic mass is located in the inferior lobe of the right
thyroid shown in transverse (A) and sagittal (B) views. The mass has an irregular border
with evidence of invasion (arrows). Abnormal, round nodes are seen in right lateral neck
in level 3 (C) and level 4 (D). The nodes were both rounded with loss of central fatty
hilum and increased peripheral vascular flow consistent with metastases (C,D).
CASTLE neoplasm , PET/CT scan of the neck. The hypermetabolic thyroid tumor (T) in the inferior
right lobe is showed in the fused PET/CT scan (top row) and CT scan (bottom row). The axial view is
shown in column A, the sagittal neck in column B and the coronal images in column C. The
metastatic nodes in right level 3 (N1) and right level 4 (N2) are both hypermetabolic
47-year-old man with metastatic left thyroid lobe with CT and PET images.
Cretinism is a condition of severely stunted physical and mental growth
due to untreated congenital deficiency of thyroid hormones (congenital
hypothyroidism) usually due to maternal hypothyroidism.
Congenital cretinism can be endemic, genetic, or sporadic. If untreated, it
results in mild to severe impairment of both physical and mental growth and
Poor length growth is apparent as early as the first year of life. Adult stature
without treatment ranges from 1 to 1.6 meters (3'4 to 5'3), depending on
severity, sex and other genetic factors. In adults, Cretinism results in mental
deterioration, swelling of the skin, loss of water and hair. Bone maturation
and puberty are severely delayed. Ovulation is impeded and infertility is
Neurological impairment may be mild, with reduced muscle tone and
coordination, or so severe that the person cannot stand or walk. Cognitive
impairment may also range from mild to so severe that the person is
nonverbal and dependent on others for basic care. Thought and reflexes are
Other signs may include thickened skin, enlarged tongue, or a protruding
Skull X ray, lateral views, in a two- year-old
child and 18-months old child demonstrating
persistent wide anterior fontanelle, mild
degree of brachycephaly in a relatively
underdeveloped skull base with increased
bone density, underdeveloped paranasal
sinuses and slightly hypoplastic facial bones,
enlarged sella turcica (Cherry sella), few
wormian bones along lambdoid suture,
relatively narrowed deploic space of parietal
bones and overcrowded teeth. B : AP view of
knee demonstrating epiphyseal dysgenesis
[irregularity and mild stippling] of the lower
femoral and upper tibial epiphyses which are
relatively small; and a delayed appearance of
the upper fibular epiphysis for age of the
patient. C, D. Plain X ray of the pelvis and
both hips in a two-year-old child (C ) and five-
year-old (D ) demonstrating epiphyseal
dysgenesis of the upper femoral epiphyses
(irregular flattened upper femoral epiphysis
which are small for age of the patient with