Thyronorm is a popular drug used against hypo and hyper thyroidism in Nepal

1. Thyroid Sonography
Dr.Amit Subedi

4. Lymphatics
Extensive, multidirectional flow
periglandular  prelaryngeal (Delphian)  pretracheal  paratracheal (along RLN) 
brachiocephalic (sup mediastinum)  deep cervical  thoracic duct

5. Embryology
• The thyroid gland primordium develops from median
eminence in the floor of primitive pharynx (a point later
known as foramen cecum at the base of tongue) during 4th
week of gestation.
• From foramen cecum, the primitive primordium descends
through anterior midline portion of the neck to reach its final
position below thyroid cartilage by 7th week of gestation.
• During this descent, the developing thyroid gland retains an
attachment to the pharynx by a narrow epithelial stalk known
as thyroglossal duct.
• This duct usually becomes obliterated by 8th-10th week of
gestation. Thyroid hormone synthesis normally begins at
about 11th week of gestation.

7. Introduction
• High-resolution ultrasonography (USG) is the most sensitive
imaging modality available for examination of the thyroid
gland and associated abnormalities.
• Ultrasound scanning is non-invasive, widely available, less
expensive, and does not use any ionizing radiation.
• Further, real time ultrasound imaging helps to guide
diagnostic and therapeutic interventional procedures in cases
of thyroid disease.

8. Indications of Thyroid Ultrasound
1. To confirm presence of a thyroid nodule when physical
examination is equivocal.
2. To characterize a thyroid nodule(s), i.e. to measure the
dimensions accurately and to identify internal structure and
vascularization.
3. To differentiate between benign and malignant thyroid
masses, based on their sonographic appearance.
4. To differentiate between thyroid nodules and other cervical
masses like lymphadenopathy, thyroglossal cyst and cystic
hygroma.

9. 5. To evaluate diffuse changes in thyroid parenchyma.
6. To detect post-operative residual or recurrent tumor in thyroid
bed or metastases to neck lymph nodes.
7. To screen high risk patients for thyroid malignancy like
patients with history of familial thyroid cancer, multiple
endocrine neoplasia (MEN) type II and irradiated neck in
childhood.
8. To guide diagnostic (FNA cytology/biopsy) and therapeutic
interventional procedures.

10. Technique
• The patient is examined supine, the neck hyperextended (a
pillow may be placed below the shoulders to achive neck
hyperextension), with a high frequency linear transducer (7-
15 MHz) that provides enough penetration (about 5 cm
depth) and excellent resolution (0.7-1 mm).
• Images are performed on gray scale and color Doppler.

11. The recommended protocol for thyroid US is as
follows:
• Transverse scans of the whole gland at the upper, mid, lower
poles and the isthmus, and side-by-side images of each lobe,
to compare echogencity and size of both lobes. Each lobe
width and AP diameters are measured .
• Longitudinal scans through each lobe, on medial, mid and
lateral planes. The length of the lobes is measured .
• Identify focal lesions, measure the main lesions and identify
the dominant one (according to size).
• Document the presence of enlarged lymph nodes or
thrombosed jugular vein.

12. • Standardized US reporting criteria should be followed
indicating: position, shape, size, margins, content,
echogenicity and vascular pattern of the whole gland and,
when present, the focal lesions.
• Nodules with malignant potential should be identified, and
FNA biopsy should be suggested to the referring physician.

13. Normal anatomy
• The normal thyroid gland consists of two lobes and a bridging
isthmus.
• Thyroid size, shape and volume varies with age and sex.
• Normal thyroid lobe dimensions are:
– 18-20 mm longitudinal and 8-9 mm antero-posterior (AP) diameter in
newborn;
– 25 mm longitudinal and 12-15 mm AP diameter at one year age; and
– 40-60 mm longitudinal and 13-18 mm AP diameter in adult
population.
• The limits of normal thyroid volume (excluding isthmus,
unless its thickness is >3 mm) are 10-15 ml for females and
12-18 ml for males.

14. • Color and power Doppler ultrasound (US) are useful to
evaluate vascularity of the thyroid gland and focal masses.
• Thyroid gland is a highly vascular structure supplied by
superior and inferior thyroid arteries. The thyroid arteries can
be visualized on color Doppler examination while the flow
parameters from these vessels can be measured by spectral
Doppler examination.
• Normally, a low resistance flow with high peak systolic
velocity (PSV) is detected in these vessels on spectral Doppler
analysis.
• The normal PSV in intra thyroid arteries ranges between 15-30
cm/second, but it can rise in certain pathologies (like Graves’
disease) to over 100 cm/sec.

15. Thyroid
measurement on
transverse and
longitudinal
scans.

16. Normal thyroid and
surrounding structures
on transverse scans. A.
RL: right lobe. LL: left
lobe. I: isthmus. E:
esophagus. B. T:
trachea. SM: strap
muscles. SCM: sterno-
cleido-mastoid muscle.
JV: jugular vein. CCA:
common carotid artery.

17. Arterial vascularization
of the thyroid gland.
A: On color Doppler, the
inferior thyroid artery is
seen.
B: On spectral display,
a low resistance flow
with a high systolic
velocity is obtained.

18. Congenital and Developmental
Anomalies of Thyroid Gland
• Pyramidal lobe
– Occassionally, rests of thyroid tissue may remain along the
course of thyroglossal duct, giving rise to an additional
thyroid lobe, the pyramidal lobe, attached to distal end of
the thyroglossal duct and left side of isthmus (seen in 50%
of population).

19. Thyroglossal duct cyst
• Incomplete degeneration of thyroglossal duct result in persistent fistulous
tract or a cyst along the path of migration of thyroid
• Anterior midline neck masses
• Occur anywhere along the course of duct, typically occur about the hyoid
bone level.
• Infrahyoid (65%); at the level of hyoid(15%); suprahyoid (20%)
• On USG- typical feature of cyst; internal echoes when proteinaceous or
infected.
• Rarely may undergo malignant degeneration (papillary)

21. Ectopic thyroid
• Ectopic thyroid represents an arrest in
usual descent of part or all of the
thyroid tissue along the normal
pathway.
• Ectopic thyroid gland develops most
commonly at sublingual (midline at
foramen cecum), suprahyoid or
infrahyoid position.
• USG shows presence of an ectopic
thyroid tissue and the normal thyroid
gland may or may not be present at
normal position.
• Ectopic thyroid may be easily detected
on CT and radionuclide scans.

22. Congenital agenesis or hypoplasia
• Congenital agenesis or hypoplasia (unilobar type or of
isthmus) of the thyroid gland may occur due to
developmental failure of all or part of thyroid gland.
• On USG, agenesis of isthmus is characterized by absence of
isthmus with the lateral lobes positioned independently on
either side of the trachea.

24. Diffuse thyroid disease
• The common conditions that present as diffuse enlargement
of the thyroid gland include multinodular goitre, Hashimoto’s
(lymphocytic) thyroiditis, de-Quervain’s subacute thyroiditis
and Graves’ disease.
• The sonographic features of these processes may be similar
but they have different biochemical profile and clinical
presentations.
• Hence, in these conditions, ultrasound findings should be
viewed in relation to clinical and biochemical status of the
patient.

25. Multinodular goitre (MNG)
• Multinodular goitre (MNG) is the commonest cause of diffuse
asymmetric enlargement of the thyroid gland.
• Females between 35-50 years of age are most commonly
affected.
• Histologically, colloid or adenomatous form of MNG is
common.
• The ultrasound diagnosis rests on the finding of multiple
nodules within a diffusely enlarged gland.
• A diffusely enlarged thyroid gland with multiple nodules of
similar US appearance and with no normal intervening
parenchyma is highly suggestive of benignity, thereby making
FNA biopsy unnecessary.
• Most of the nodules are iso-or hyper-echoic in nature; when
enlarged provide heterogeneous echo pattern to the gland.

26. • These goitrous nodules often undergo degenerative changes
that correspond to their USG appearances:
– cystic degeneration gives anechoic appearance to the
nodule
– hemorrhage or infection within the cyst is seen as moving
internal echoes/septations,
– colloidal degeneration produces comet-tail artifact
– dystrophic calcification is often coarse or curvilinear.

29. • Vascular compression due to follicular hyperplasia leads to
focal ischemia, necrosis and inflammatory change.
• The assessment of nodule vascularity is very useful in
differentiating MNG from multifocal carcinoma.
• Nodule with intrinsic vascularity and other features of
malignancy can be targeted for biopsy, in preference to other
nodules.

30. Graves’ disease
• Most common of the autoimmune disorders.
• Peak: 3rd to 5th decade; F>M.
• Imaging features:
• USG:
• Inhomogenous echotexture; parenchyma may be diffusely
hypoechoic due to extensive lymphocytic infiltration.
• thyroid is diffusely enlarged (2-3 times its normal size),
• Colour doppler:
• Hypervascular pattern(thyroid inferno).
• Spectral doppler: PSV >70 cm/sec
• However, no correlation betn the degree of thyroid hyperfunction
and the extent of hypervascularity and blood flow velocities.
• Doppler can be used to monitor the therapeutic response:
significant decrease in flow velocities in superior and inferior
thyroidal arteries after medical treatment.

31. Color flow ultrasonogram in the graves disease. Generalized hypervascularity is visible
throughout the gland, which often can be heard as a hum or bruit with a stethoscope
•

32. Hashimoto’s thyroiditis
• Hashimoto’s thyroiditis (chronic lymphocytic thyroiditis) is an
autoimmune disorder leading to destruction of the gland and
hypothyroidism.
• It occurs predominantly in females over 40 years of age.
• Painless, diffuse enlargement of thyroid gland is the most
common clinical presentation.
• Diagnosis of Hashimoto’s thyroiditis is confirmed by
demonstration of serum thyroid antibodies and
antithyroglobulin antibodies.

33. • The characteristic US appearance is focal or diffuse glandular
enlargement with coarse, heterogeneous and hypoechoic
parenchymal echo pattern.
• Presence of multiple discrete hypoechoic micronodules (1-6
mm size) is strongly suggestive of chronic thyroiditis.
• Fine echogenic fibrous septae may produce a
pseudolobulated appearance of the parenchyma.

34. • Color Doppler may demonstrate slight to markedly increased
vascularity of the thyroid parenchyma.
• Increased vascularity seems to be associated with
hypothyroidism, likely due to trophic stimulation of
thyroid-stimulating hormone.
• Small atrophic gland represents end stage Hashimoto’s
thyroiditis.
• Occasionally, nodular form of Hashimoto’s thyroiditis may
occur; within a sonographic background of diffuse
Hashimoto’s thyroiditis or within normal thyroid parenchyma.

37. De Quervain’s thyroiditis
• De Quervain’s thyroiditis (subacute granulomatous thyroiditis)
characteristically presents with painful swelling in lower neck,
fever and constitutional symptoms, typically following a viral
illness.
• There may be features of thyrotoxicosis or hypothyroidism
depending on phase of the illness. Initially there is
thyrotoxicosis, followed by hypothyroidism.
• USG examination shows characteristic focal hypoechoic areas
(map like) and enlargement of one or both thyroid lobes.
• Color Doppler sonography shows decrease or absent blood
flow within abnormal map-like hypoechoic areas.
• Complete recovery is characteristic and occurs in weeks to
months. In recovery phase, thyroid appearance returns to
normal.

38. Acute thyroiditis (suppurative/infectious
thyroiditis)
• Acute thyroiditis (suppurative/infectious thyroiditis) is rare
and occurs due to suppurative infection of the thyroid.
• In children and adults, the most common cause is infection of
pyriform sinus fistula (a congenital branchial pouch
abnormality).
• In elderly, long standing goitre and degeneration in thyroid
malignancy are risk factors.
• Clinically, patient presents with acute onset fever, thyroid
pain, asymmetric swelling of the gland (predominantly left
sided) and regional lymphadenopathy.

39. • On USG the involved lobe appears heterogeneous and
hypoechoic. Abscess and cyst formation may be seen. Rarely,
retropharyngeal abscess, tracheal obstruction, jugular vein
thrombosis and mediastinitis may complicate acute
thyroiditis.

41. Nodular thyroid disease
• Characterized by the presence of one or more
palpable or non palpable nodules in the
substance of thyroid gland.
• F:M= 6:1
• 80-85%: hyperplasia of the gland
• 15-20%: adenomas and carcinomas.
• Aetiology: iodine def (endemic), hereditary
familial forms, poor iodine utilization d/t
medications.

42. Imaging features
• Nodular thyroid disease is most commonly encountered pathology
of thyroid.
• USG:
– confirm presence of thyroid nodule.
– diff thyroid nodules from other cervical masses.
– diff benign vs. malignant nodules.
• Typical benign nodules:
– Well marginated
– Mostly cystic or hypoechoic masses
– Almost always contain internal debris.
– A sonolucent halo around a isoechoic nodule or a solid hyperechoic
nodule. The halo represents perinodular blood vessels and mild
edema or compression of adjacent normal parenchyma.

43. Imaging features(..contd)
• Calcifications : non specific and present in 10-15% of all
benign and malignant thyroid nodules.
– Peripheral and egg shell like calcification: benign
– Fine and punctate: malignant
• Colour flow patterns : Originally three colour flow patterns
were described within thyroid nodules:
Type I-no flow detected within the nodule
Type II- peri-nodular arterial flow pattern
Type III- intra-nodular flow with multiple vascular poles,
chaotic arrangement, with or without peri-nodular flow
• Type I and II are mostly seen in benign hyperplastic nodules
whereas Type III flow pattern is generally identified in
malignant nodules.

44. FIGURE . Hyperplastic (adenomatous)
nodule.
Longitudinal ultrasound images.
A, Oval homogeneous nodule(arrows)
with thin, uniform halo.
B, Three hyperechoic nodules, typical
of hyperplasia.
C, Solitary hyperechoic nodule, which
was benign on fine-needle aspiration
biopsy.

45. A. Typical benign calcification – peripheral/ “egg shell”. B. Solid
hypoechoic lesion containing micro-calcification – diagnosis – papillary
carcinoma

46. A. Benign colour
flow pattern –
note hyperechoic
nodule relative to
thyroid, halo,
peripheral colour
flow with no
significant intra
nodular flow
B. Malignant intra
nodular, chaotic
blood flow
pattern.

47. "Ring down” sign
within solid
component of a
cystic colloid
nodule.
• A major constituent of benign thyroid nodules is colloid. Colloid causes a "ring
down" artifact or sign, typically within the cystic element of a nodule.
• Care needs to be taken by the operator however in ensuring that the
echogenic "ring down" sign is not mistaken for the microcalcification that is
pathognomonic of papillary carcinoma of the thyroid.

48. • Thyroid incidentalomas:
– Incidentally detected thyroid nodules during neck USG.
– Such nodules in patients with prior history of irradiation or
thyroid cancer require USG guided FNAC.
– In others, the decision to biopsy is based on size(>1.5cm)
and presence of sonographic features s/o of malignancy(
hypoechoic pattern, incomplete peripheral halo, irregular
margins, internal microcalcifactions).
– Benign appearing incidentolomas (<1.5 cm)should be
followed clinically at 6 mo and anually thereafter.

49. Features Benign Malignant
Internal contents
Purely cystic ++++ +
Cystic with thin septa ++++ +
Mixed +++ ++
Comet tail artefact +++ +
Echogenecity
Hyperechoic ++++ +
Iso +++ ++
Hypo +++ +++

50. Halo
Thin halo ++++ ++
Thick incomplete
Margin
+ +++
Well defined +++ ++
Ill defined ++ +++
Calcification
Eggshell ++++ +
Coarse +++ +
Microcalcification ++ ++++
Doppler
Peripheral flow +++ ++
Internal flow ++ +++

51. Thyroid adenomas
• True benign neoplasms; encased by a fibrous capsule.
• May be functioning or non functioning but are usually
solitary and non functioning.
• Young and middle aged adults.
• Usually less than 3 cm in diameter, have well defined
margins, and may involute, become cystic and may
develop internal hemorrhage, necrosis, calcification or
fibrosis.

52. Imaging features
• USG:
– Most are hyperechoic or isoechoic (carcinomas are
hypoechoic with poorly defined borders)
– Almost 50% are isoechoic; visible due to hypoechoic
peripheral halo. The halo is due to fibrous capsule and
blood vessels( can be seen by colour doppler)
• CT Scan:
– Solid or cystic when it has degenerated.
• MRI:
– Increased signal intensity in T2, often heterogenous.

53. • Benign follicular adenoma is a true thyroid
neoplasm characterised by compression of
adjacent tissues and fibrous encapsulation.
• Subtypes of follicular adenoma:
– Fetal adenoma
– Hurthle cell adenoma
– Embryonal adenoma
• FNA cannot diff adenoma from carcinoma due to
similar cytological appearance; HPE is required.

54. Sonogram displaying a palpable, asymptomatic thyroid nodule shows a solid mass in the
thyroid, with a completely surrounding halo. The final diagnosis was a benign adenoma of
the right lobe

55. Power Doppler sonogram shows peripheral vascularity but no detectable flow
in the tumor. The final diagnosis was benign thyroid adenoma
•

56. Thyroid cancer
• Uncommon accounting for only 0.5% of all cancer deaths.
• Female preponderance
• Peak incidence: young women 25-35 yrs
• Radiation exposure is the most important etiological factor, with the
incidence increasing with higher doses of radiation
• Peak incidence occurs 5-30 years after irradiation.
• Other risk factors: iodine excess, genetic predisposition and alcohol
excess.
• Thyroid cancer spreads first to the lymphatic cervical nodes; distal
metastases are infrequent-2-3% of cases, mostly to bones and lungs.

57. Papillary carcinoma
• Most common type of thyroid cancer, accounting for 60-80%
• Females, with a female-to-male ratio of 2-4:1
• Age 20-40 years.
• most common clinically silent thyroid cancers are papillary
carcinomas, which are usually smaller than 1 cm
• nodal involvement occurs in 50% of pts at the time of diagnosis and
does not appear to affect prognosis.
• Although recurrence occurs in 15-25% of patients, the long-term
outcome is believed to be exceedingly good, with a survival rate
higher than 90% after 20 yrs

58. • Metastatic spread to the regional nodes occurs in as many as 50%
of the patients, with an approximately doubled incidence in children.
• Hematogenous spread in 5-10% of patients, with a propensity for
the lung and bones.
• Treatment usually involves surgical resection.
• Suppressive hormonal therapy has been advocated, although its
effectiveness has not been confirmed.

59. Imaging features
• USG:
– Hypoechogenecity ( 90% cases) due to closely packed cell content with
minimal colloid substance)
– Microcalcifications: tiny punctate hyperechoic foci with or without acoustic
shadows.
– Hypervascularity ( 90% cases) with disorganized vascularity.
– Cervical LN metastasis: may contain tiny, punctate echogenic foci d/t
microcalcifications. Occ cystic due to extensive degeneration.
• Cross sectional imaging: local as well as distant spread.
• Radionuclide imaging:
– Well-differentiated papillary and follicular tumours usually take up radio-
iodine, but to a much lesser degree than normal thyroid.

60. a. A hypoechogenic nodule with
poorly defined margin without a
sorrounding halo is detected in
the right thyroid lobe.
b. Microcalcifications without
acoustic shadowing are seen
(arrowheads).
c. A disorganized rich internal
vascularity is seen on Power
Doppler. Papillary carcinoma was
diagnosed on fine needle
aspiration biopsy (FNAB).

61. Follicular carcinoma
• Incidence is 5% of thyroid neoplasms if adequate iodine is ingested;
however, the incidence can be as high as 40% of malignancies in
iodine-deficient populations.
• Women are affected 2-3 times more often than men.
• occurs in a slightly older age group 40-50 yrs
• Although the neoplasm may be detected as a result of mass effect, it
is more likely to be clinically silent at initial presentation.
• Nodal disease occurs in approximately 10% of patients with follicular
carcinoma.
• Hematogenously spread metastatic disease in the lung, brain, and
bone occurs in fewer than 5%
• Differentiating follicular carcinoma from benign follicular adenoma
can be difficult.
• The diagnosis of malignancy relies on the demonstration of vascular
invasion or full-thickness capsule invasion.

62. • The two variants of follicular carcinoma differ greatly
in histology and clinical course.
• Minimally invasive follicular carcinomas are
encapsulated, and only the histologic demonstration
of focal invasion of capsular blood vessels of the
fibrous capsule itself permits differentiation from
follicular adenoma.
• Widely invasive follicular carcinomas are not well
encapsulated, and invasion of the vessels and the
adjacent thyroid is more easily demonstrated.

63. Imaging features
• Usg- hypoechoic mass in 45% and rest iso, nodule
with ill defined borders, heterogeneous internal
echoes, irregular thick capsule, tortuous intranodal
and perinodal vsls
• 5 yr survival for encapsulated variant: 90%
• Poor prognosis for invasive variants.

64. a. A bilobular hypoechoic nodule
with coarse calcifications (arrow)
is seen in the left lobe.
b. b. Disorganized hypervascular
network on power Doppler in
transverse (b) and longitudinal (c)
scans. FNA was performed
yielding a diagnosis of follicular
tumor.

65. Medullary carcinoma
• represents 3-10% of thyroid malignancies, is derived from
parafollicular cells (C cells)
• Calcitonin levels may be increased; the levels are reported to be
correlated with the tumor load.
• Although more common in women than in men, medullary
carcinoma is less sex specific than other thyroid malignancies.
• A familial basis is found in 10-20% of patients, with an autosomal
dominant inheritance pattern.
• component of multiple endocrine neoplasia (MEN) syndrome types
IIA and IIB and is associated with pheochromocytoma and
parathyroid adenoma or parathyroid hyperplasia

66. • Regional lymph node spread is present in 50% of patients at the
time of diagnosis
• Hematogenous spread to the liver, bone, and lung may occur.
• reported 5-year survival rates is less than 65%- 80%
• poor prognosis is associated with MEN syndrome type IIB,
pleomorphic necrosis, and increased mitotic activity.
• USG- Typically hypoechoic with coarse calcifications

67. a. A solitary highly
hypoechoic well
delimited oval nodule is
seen in the left lobe.
b. Sparced peripheral and
central vascularization
seen on color Doppler.
Medullary carcinoma
was diagnosed on US-
guided FNA

68. Anaplastic carcinoma
• extremely aggressive tumors and represent 8-16% of
thyroid neoplasms
• prevalent in regions in which goiter is endemic
• seen in patients aged 60-80 years, they occur slightly
later in life, compared with other thyroid neoplasms
• strong female predominance with F:M= 3:1
• Regional nodal disease and distant metastases are seen
in 50-69% of patients at the time of diagnosis
• Unlike other thyroid neoplasms, no effective treatment is
available
• most patients die within the first year.

69. Imaging features
• In USG- Large, hypoechoic mass, Encase or invade blood
vessels, Invade neck muscles
• On CT - calcification (60%) and necrosis(75%), extension of
tumour
• Do not concentrate radioiodine.

70. a. Transverse scan. b. Longitudinal scan. A large hypoechoic
undefined tumor invading the adjacent muscles is seen in the right
lobe. The histological diagnosis was anaplastic carcinoma of the
thyroid gland.

71. Thyroid lymphoma
• almost always non-Hodgkin lymphomas
• account for 4-10% of thyroid malignancies
• women older than 50 years are affected in association with
Hashimoto thyroiditis
• present with a rapidly growing neck mass, which may cause
symptoms of obstruction
• In 70-80% of pts., arises in a preexisting chronic thyroiditis with
subclinical or overt hypothyroidism
• prognosis depends on the stage of the disease at diagnosis.
• 5-year survival rate ranges from 89% in early disease to only 5% in
disseminated disease
• Signs of cervical invasion in the late stages are also similar to those
of an undifferentiated thyroid carcinoma.

72. • On US, appear as hypoechoic mass with lobulated margins and
large, anechoic necrotic areas and enlargement of gland
• Doppler US findings are unremarkable
• Signs of cervical invasion in the late stages also are similar to those
of an undifferentiated thyroid carcinoma; however, thyroid tissue
surrounding undifferentiated tumors is a normal finding, whereas
tissue surrounding lymphomas shows evidence of chronic thyroiditis

73. • FNAC remains the key procedure for the diagnosis of thyroid
• Most accurate imaging method for staging is CT
• Lymph node involvement is depicted equally well by MRI or CT scan
and both are superior to US
• Tumor invasion of the esophagus- MRI and CT& but not on
sonograms
• MRI- used to stage the disease and to assess adenopathy and
esophageal involvement.
• Gallium-67 scintigraphy- useful adjunct to imaging, because thyroid
lymphoma is typically cold in iodine and technitium scans.

74. A, Transverse image of
left lobe of the thyroid
shows diffuse mass
enlarging the lobe and
extending
into the soft tissues
(arrows) surrounding the
common carotid artery
B, Contrast-enhanced
CT scan shows a
hypovascular mass in the
left thyroid lobe and soft
tissue encasement of the
carotid artery.

75. Thyroid metastasis
• rare
• usually a late manifestation of primary cancer
• most metastases are derived from disseminated disease in the liver,
bones, lungs, and cervical lymph nodes.
• Incidence of known primary cancer in these patients is 2-17%.
• Common primary sites include the skin (melanoma, 39%), breast
(21%), and kidney (renal cell carcinoma, 10%)

76. Interventions
• FNA is used because of the inability of imaging to precisely define
the nature of the thyroid nodule.
• For palpable nodules, FNA can be performed with palpation
• Guided FNA provides samples for cytologic studies.
• procedure is safe and inexpensive and provides direct information.
The sensitivity and specificity are 65-98% and 72-100%,
respectively.
• The overall accuracy of cytologic diagnosis approaches 95%.

77. US-guided FNA is indicated:
• When the nodule is not palpable with certainty in patients
with a family history of thyroid carcinoma,
• Those who underwent previous neck irradiation
• Individuals with nonpalpable sonographically depicted
nodules.
• Previous non diagnostic results at palpation-guided FNA.
• In the procedure, the needle can be placed in the
peripheral solid and cellular portions of the nodule that
provide the greatest diagnostic yield when aspirated.
• No serious complications have been reported with FNA

78. US-guided thyroid nodule alcohol ablation
• Cystic nodules:
• As an alternative therapy in cystic thyroid nodules in which malignancy has been
ruled out by FNB.
• Following complete aspiration of cyst fluid with a fine needle, 95% sterile ethanol
(approx. 30-60% of aspirated fluid ) is injected under USG guidance.
• The ethanol can be reaspirated within 1-2 days or permanently left in place.
• Can be repeated once or twice in large cystic cavities at interval of several weeks.
• Well tolerated, success rate: 72-95%
• Autonomous nodules:
• Ethanol injection treatment of choice in older pts where surgery is C/I, pregnancy
or in pts with large autonomous nodules(>40 ml).
• Cervical nodal mets from papillary ca can also be treated with ethanol injection.

79. • The adverse effects
– transient pain or a burning sensation at the site of injection( most
common)
– Local hematoma, transient dysphonia, and transient headache .
• The most serious complication is recurrent laryngeal nerve palsy,
reported in 1-4% of procedures.
• The complication is usually transient, and full recovery typically
occurs within 1-3 months
• The aggravation of toxic symptoms is reported in the treatment of
thyrotoxic nodules. Thyroid crisis was reported in a single case
• When severely thyrotoxic patients are treated, the use of beta
blockers may be appropriate.

80. Sonoelastography
• Recently, a new sonographic technique called sonoelastography (or
elastosonography) has been applied to the study of thyroid nodules,
following the results achieved for breast nodules.
• Sonoelastography provides information on tissue elasticity, based on the
premise that pathologic processes such as cancer alter the physical
characteristics of the involved tissue.
• Sonoelastographic measurements are performed during the ultrasound
examination, using the same ultrasound machine and the same
transducer.
• The operator exerts light pressure with the probe and selects the portion
of the image that includes the nodule to be evaluated. The purpose is to
acquire two sonographic images (before and after tissue compression) and
track tissue displacement by assessing the propagation of the beam,
providing accurate measurement of tissue distortion.

81. • The ultrasound elastogram is displayed over the typical B-
mode gray-scale ultrasound scan in a color scale and classified
by using the elasticity score.
• Four elastographic patterns have been classified as follows
• Pattern 1: Elasticity in the whole nodule .
• Pattern 2: Elasticity in a large part of the nodule, with
inconstant appearance of anelastic areas.
• Pattern 3: Constant presence of large anelastic areas at the
periphery .
• Pattern 4: Uniformly anelastic
• In literature reports, 78% to 100% of benign nodules had a
score of 1 to 2, whereas 88% to 96% of malignant nodules had
a score of 3 to 4.

82. Use of ultrasound
elastography on thyroid
nodule: benign nodular
hyperplasia (pattern
1).
A, Conventional longitudinal
B-mode sonogram with color
Doppler shows a hypoechoic
solid nodule (arrows) with
peripheral halo,
internal comet-tail artifacts,
and perilesional blood flow
pattern.
B, Longitudinal ultrasound
elastography at same
location demonstrates a
“soft” color pattern 1.

83. Use of ultrasound elastography on thyroid nodule: benign nodular
hyperplasia with cystic changes (pattern 2). Left half of image
shows a cystic, poorly defined nodule on conventional B-mode
gray-scale sonogram. Right half of sonoelastogram of the nodule shows
a predominantly elastic (green) pattern with a few internal anelastic
bandlike areas.

85. Thank you