Thyroid, Parathyroid, Thyroid, Parathyroid, and Neckand Neck
Tanya NolanTanya Nolan
Thyroid Gland AnatomyThyroid Gland Anatomy
Anatomic VariationsAnatomic Variations Thyroglossal Duct Thyroglossal Duct
CystCyst Thyroglossal duct fails to Thyroglossal duct fails to
involute completelyinvolute completely
AthyrosisAthyrosis Absence of Thyroid Absence of Thyroid
glandgland
Pyramidal LobePyramidal Lobe Absence of Absence of
IsthmusIsthmus Ectopic GlandEctopic Gland
Neck AnatomyNeck Anatomy
Normal AnatomyNormal Anatomy
Normal AnatomyNormal Anatomy
Function and PhysiologyFunction and Physiology Maintains body metabolism, growth, and Maintains body metabolism, growth, and
development development synthesis, storage, & secretion of thyroid synthesis, storage, & secretion of thyroid
hormoneshormones1.1. Thyroid gland traps iodine (used for synthesis) Thyroid gland traps iodine (used for synthesis)
2.2. Produces triiodothyronine (T3) & thyroxine (T4) Produces triiodothyronine (T3) & thyroxine (T4)
3.3. Thyroid hormone released into bloodstream via action Thyroid hormone released into bloodstream via action of thyrotopin (TSH) produced by the pituitary glandof thyrotopin (TSH) produced by the pituitary gland
Thyroxine (T4)Thyroxine (T4) Iodine + Tyrosine (amino acid)Iodine + Tyrosine (amino acid) Combines with protein thyroglobulin & stored.Combines with protein thyroglobulin & stored.
Increases carbohydrate burnIncreases carbohydrate burn Breaks down proteins for energyBreaks down proteins for energy Regulates fat metabolism Regulates fat metabolism Accelerates body growth (especially nervous tissue)Accelerates body growth (especially nervous tissue) Increases nervous system reactivityIncreases nervous system reactivity
CalcitoninCalcitonin Produced by parafollicular cells (C cells of Produced by parafollicular cells (C cells of
thyroid gland) in response to high calcium thyroid gland) in response to high calcium levelslevels
DecreasesDecreases the concentration of calcium in the concentration of calcium in the blood by inhibiting bone break down (less the blood by inhibiting bone break down (less Ca absorbed)Ca absorbed)
What happens when blood What happens when blood
Calcium concentrations are Calcium concentrations are
HIGH?HIGH?
Thyroid Stimulating Thyroid Stimulating Hormone (TSH)Hormone (TSH)
Produced by the Produced by the anterior anterior pituitary glandpituitary gland
Regulated by the Regulated by the thyrotropin-releasing thyrotropin-releasing factor (TRF) produced factor (TRF) produced by the by the hypothalmushypothalmus
TRF regulated by the TRF regulated by the basal metabolic rate.basal metabolic rate.
Feedback SystemFeedback System>>Decreased Metabolic Rate Decreased Metabolic Rate
LOW OR HIGH Concentration of Thyroid LOW OR HIGH Concentration of Thyroid Hormone (Thyroxine)?Hormone (Thyroxine)?
>Hypothalmus releases Thyrotropin-Releasing Factor(TRF)>Hypothalmus releases Thyrotropin-Releasing Factor(TRF)
Thyroid Stimulating Hormone (TSH) Thyroid Stimulating Hormone (TSH) Released by Released by __________?__________?
>Increase in Thyroid Hormone >Increase in Thyroid Hormone
Blood Concentration Normal Blood Concentration Normal
Basal Metabolic Rate NormalBasal Metabolic Rate Normal
>TRF inhibited >TRF inhibited
Lab TestsLab Tests Nuclear MedicineNuclear Medicine
Most accurate for T3 & T4 levels. Most accurate for T3 & T4 levels. Radioactive iodine injected into Radioactive iodine injected into
the bloodstream & % of uptake the bloodstream & % of uptake monitored by gamma camera. monitored by gamma camera.
HOT NODULEHOT NODULE: A : A
hyperfunctioning nodule or hyperfunctioning nodule or COLD NODULECOLD NODULE: hypoactive : hypoactive
nodule.nodule.
What type of nodule is What type of nodule is MOSTMOST suspicious of suspicious of carcinoma? carcinoma?
Lab TestsLab Tests Triiodothyronine (T3)Triiodothyronine (T3)
Normal RIA 80-160 ng/dl; RU: 25-35% relative uptakeNormal RIA 80-160 ng/dl; RU: 25-35% relative uptake
Serum Thyroxine (T4)Serum Thyroxine (T4) Normal Serum T4: 5-11 mg/dl. Normal Serum T4: 5-11 mg/dl. Elevated levelsElevated levels seen in hyperthyroidism and acute thyroiditis. seen in hyperthyroidism and acute thyroiditis. Low levelsLow levels are seen in hypothyroidism, myxedema, cretinism, chronic are seen in hypothyroidism, myxedema, cretinism, chronic
thyroiditis, and occasionally in subacute thyroiditis.thyroiditis, and occasionally in subacute thyroiditis.
Serum CalcitoninSerum Calcitonin Elevated levelsElevated levels of calcitonin are diagnostic of medullary carcinoma of of calcitonin are diagnostic of medullary carcinoma of
the thyroidthe thyroid
Serum Thyroid Stimulating HormoneSerum Thyroid Stimulating Hormone Normal Serum TSH < 5mU/mlNormal Serum TSH < 5mU/ml TSH level is indicative of thyroid reserve. It is the TSH level is indicative of thyroid reserve. It is the most accurate test most accurate test
for for primary primary hypothyroidismhypothyroidism
Indications for Indications for Sonographic Sonographic ExaminationExamination
Palpable enlargementPalpable enlargement Abnormal Thyroid Hormone Level(s)Abnormal Thyroid Hormone Level(s) Palpable mass in neck / thyroidPalpable mass in neck / thyroid Swelling of neckSwelling of neck Asymmetry of neckAsymmetry of neck Redness and/or tendernessRedness and/or tenderness
Sonographic TechniqueSonographic Technique EquipmentEquipment
High frequency (7.5-15 MHz or higher) linear High frequency (7.5-15 MHz or higher) linear TransducerTransducer
Patient PositionPatient Position Supine with neck extendedSupine with neck extended
ViewsViews Longitudinal and Transverse images of bilateral Longitudinal and Transverse images of bilateral
lobes & Transverse view of the isthmuslobes & Transverse view of the isthmus Demonstrate relational anatomyDemonstrate relational anatomy
Normal Normal ThyroidThyroid
Adult Thyroid
40-60 mm long
13-18 mm AP
Isthmus 4-6 mm AP
Newborn: 18-20 mm long; 8-9 mm AP
Age 1: 25 mm long; 12-15 mm AP
Nontoxic GoiterNontoxic Goiter Simple, Colloid, or MultinodularSimple, Colloid, or Multinodular
Enlargement of entire gland without Enlargement of entire gland without producing nodularity and without evidence of producing nodularity and without evidence of functional disturbance (euthyroid)functional disturbance (euthyroid)
CausesCauses Lack of IodineLack of Iodine
Compensatory increase of TSH = follicular cell Compensatory increase of TSH = follicular cell hypertrophyhypertrophy
Sporatic GoiterSporatic Goiter Diffuse, Uninodular, or multinodularDiffuse, Uninodular, or multinodular Ingestion of Substances, hereditary enzyme Ingestion of Substances, hereditary enzyme
defectsdefects Simple Goiters may evolve = Simple Goiters may evolve =
Multinodular GoitersMultinodular Goiters Calcification, Degeneration, Fibrosis, Calcification, Degeneration, Fibrosis,
and Hemorrhageand Hemorrhage
Thyrotoxicosis / Thyrotoxicosis / HyperthyroidismHyperthyroidism
Over secretion of thyroid hormonesOver secretion of thyroid hormones Clinical SignsClinical Signs
Dramatic increase in metabolic rateDramatic increase in metabolic rate Weight LossWeight Loss Increased appetiteIncreased appetite Nervous energyNervous energy TremorTremor Excessive sweatingExcessive sweating Heat intoleranceHeat intolerance Cardiac PalpitationsCardiac Palpitations Exopthalmos (protruding eyes)Exopthalmos (protruding eyes)
CausesCauses Abnormal hormone secretion (entire gland out of control)Abnormal hormone secretion (entire gland out of control) Localized neoplasm caused by overproduction of hormonesLocalized neoplasm caused by overproduction of hormones Grave’s diseaseGrave’s disease
Toxic Multinodular GoiterToxic Multinodular Goiter“Grave’s Disease”“Grave’s Disease”
Clinical SignsClinical Signs Women over 30Women over 30 HypermetabolismHypermetabolism ExopthalmosExopthalmos Cutaneous formations (periorbital and dorsum of feet)Cutaneous formations (periorbital and dorsum of feet)
CausesCauses Autoimmune Autoimmune hyperthyroidismhyperthyroidism
Sonographic FindingsSonographic Findings Diffuse enlargementDiffuse enlargement Hypoechoic without Hypoechoic without palpable nodulespalpable nodules Markedly increased Markedly increased vascularity vascularity (“thyroid (“thyroid inferno”)inferno”)
HypothyroidismHypothyroidism Lack of secretion of thyroid hormonesLack of secretion of thyroid hormones
Clinical SignsClinical Signs Myxedema (skin and tissue disorder)Myxedema (skin and tissue disorder) Weight gainWeight gain Hair lossHair loss Increased tissue around the eyesIncreased tissue around the eyes LethargyLethargy Intellectual and motor slowing Intellectual and motor slowing Cold IntoleranceCold Intolerance ConstipationConstipation Deep, husky voiceDeep, husky voice
Causes Causes Primary = Thyroid hormone failure Primary = Thyroid hormone failure Secondary = Diseases of the hypothalmus or pituitarySecondary = Diseases of the hypothalmus or pituitary
TreatmentTreatment Synthetic thyroid hormone can reverse the conditionSynthetic thyroid hormone can reverse the condition
ThyroiditisThyroiditis Most common cause of primary hypothyroidism in Most common cause of primary hypothyroidism in
iodine rich areas of the worldiodine rich areas of the world Inflammation of the thyroid causing swelling and Inflammation of the thyroid causing swelling and
tendernesstenderness May be associated with lymphomaMay be associated with lymphoma
CausesCauses InfectionInfection AutoimmuneAutoimmune
TypesTypes De QuervainsDe Quervains Hashimoto’sHashimoto’s
De Quervain’sDe Quervain’s Clinical SignsClinical Signs
Usually viral Usually viral Diffuse enlargementDiffuse enlargement Tenderness / mild to severe painTenderness / mild to severe pain Transient hyperthyroidismTransient hyperthyroidism Gradual or fairly abrupt onsetGradual or fairly abrupt onset
Hashimoto’sHashimoto’s Increased risk for malignant diseaseIncreased risk for malignant disease Clinical SignsClinical Signs
Most common form of thyroiditisMost common form of thyroiditis Autoimmune – chronic inflammationAutoimmune – chronic inflammation Diffuse enlargementDiffuse enlargement possibly asymmetricpossibly asymmetric PainlessPainless may develop mild pain over timemay develop mild pain over time Eventual hypothyroidismEventual hypothyroidism Young – middle aged femalesYoung – middle aged females
Sonographic Findings:
1. Increased Vascularity with Color Doppler
2. Texture is course and homogenous with multiple ill-defined hypoechoic areas separated by thick fibrous strands
3. Over time, the gland becomes fibrotic, ill-defined, and heterogeneous
Thyroid Disease and Pregnancy
• 2nd most common endocrinopathy that affects women of reproductive age.
Increase TBG (Thyroid Binding Globulin)Decreased TSH between weeks 8-14Reduced plasma iodine
• Increased gland size in 13% women
• Post Partum Thyroiditis
Benign MassesBenign MassesCysts and Cystic NodulesCysts and Cystic Nodules
Sonographic AppearanceSonographic Appearance Purely anechoic areas (serous / colloid fluid), well-Purely anechoic areas (serous / colloid fluid), well-
defined walls, & distal enhancement.defined walls, & distal enhancement. Fluid levels (hemorrhage)Fluid levels (hemorrhage) FNA / Ethanol InjectionFNA / Ethanol Injection
Degenerative Colloid Cysts
Benign MassesBenign MassesAdenomasAdenomas
Most common solid thyroid massMost common solid thyroid mass Encapsulated nodule Encapsulated nodule
compression of adjacent tissuescompression of adjacent tissues fibrous encapsulationfibrous encapsulation
Clinical FeaturesClinical Features Most patients euthyroid or hyperthyroidMost patients euthyroid or hyperthyroid Slow growing – must be 0.5 – 1 cm to be palpatedSlow growing – must be 0.5 – 1 cm to be palpated
Sonographic AppearanceSonographic Appearance Variable sonographic appearanceVariable sonographic appearance Follicular carcinoma is indistinguishable from an Follicular carcinoma is indistinguishable from an
adenomaadenoma
AdenomasAdenomas Well circumscribed; circular Well circumscribed; circular
shapedshaped Peripheral haloPeripheral halo (edema of (edema of
compressed tissue)compressed tissue) Increased Color Flow Increased Color Flow Cystic DegenerationCystic Degeneration Rim CalcificationRim Calcification Homogeneous with variable Homogeneous with variable
size; Hyperechoicsize; Hyperechoic Slow growing unless Slow growing unless
hemorrhage occurs (sudden hemorrhage occurs (sudden painful enlargement)painful enlargement)
MalignaMalignant nt
MassesMasses
Carcinoma of the thyroid is rare!Carcinoma of the thyroid is rare! Risk of malignancy decreases with Risk of malignancy decreases with multiplemultiple nodules nodules A A solitary thyroid solitary thyroid nodule in the presence of nodule in the presence of cervical adenopathycervical adenopathy
on the same side suggests on the same side suggests malignancymalignancy Clinical FindingsClinical Findings
Asymptomatic noduleAsymptomatic nodule HoarsenessHoarseness History of exposure to low dose ionizing radiationHistory of exposure to low dose ionizing radiation Solitary fixed, rapidly enlarging nodule in patient under 14 years or over Solitary fixed, rapidly enlarging nodule in patient under 14 years or over
65 years of age65 years of age
Papillary CarcinomaPapillary Carcinoma Most common thyroid malignancyMost common thyroid malignancy
Sonographic FindingsSonographic Findings HypoechoicHypoechoic MicrocalcificationsMicrocalcifications HypervascularityHypervascularity Possible cervicalPossible cervical
lymph node metastasislymph node metastasis
Medullary Carcinoma Medullary Carcinoma C - CellsC - Cells
Clinical FindingsClinical Findings Hard, bulky massHard, bulky mass Abnormal serum calcitonin Abnormal serum calcitonin
levelslevels
Sonographic FindingsSonographic Findings Solid mass Solid mass CalcificationsCalcifications LymphadenopathyLymphadenopathy
Metastasis Metastasis to Lymph to Lymph
NodesNodes
How does the appearance of a normal lymph node differ from an abnormal lymph node?
Normal
Anaplastic (Undifferentiated) Anaplastic (Undifferentiated) CarcinomaCarcinoma
Clinical signsClinical signs > 50 years of age> 50 years of age Hard, fixedHard, fixed Rapid growthRapid growth Pain, pressure, Pain, pressure,
tendernesstenderness Locally invasiveLocally invasive
Sonographic FindingsSonographic Findings Hypoechoic mass, Hypoechoic mass,
possibly irregularpossibly irregular Diffuse glandular Diffuse glandular
involvementinvolvement Invasion of Invasion of
surroundingssurroundings
Features of Benign/Malignant Features of Benign/Malignant NodulesNodules
Feature Benign Malignant
Internal ContentsPurely CysticCystic with Thin SeptaMixed Solid and CysticComet Tail Artifact
++++++++++++++
+++++
EchogenicityHyperechoicIsoechoicHypoechoic
++++++++++
++++++
HaloThin HaloThick Incomplete Halo
+++++
+++++
MarginWell DefinedPoorly Defined
+++++
+++++
CalcificationEggshellCourseMicrocalcifications
+++++++++
++++++
Doppler Flow PatternPeripheralInternal
+++++
+++++
Parathyroid GlandParathyroid Gland 4 small masses on 4 small masses on posterior posterior
surface of the lateral lobessurface of the lateral lobes PhysiologyPhysiology
Monitors Monitors Calcium Calcium MetabolismMetabolism
Produces Parathyroid Produces Parathyroid HormoneHormoneSerum Calcium LowSerum Calcium LowPTH SecretedPTH Secreted
Releases calcium from Releases calcium from bones bones
Changes intestinal tract Changes intestinal tract absorptionabsorption
Parathyroid GlandParathyroid Gland Texture similar to overlying Texture similar to overlying
thyroid thyroid (size <4 mm glands are usually (size <4 mm glands are usually not seen)not seen) Be careful to evaluate in sagittal Be careful to evaluate in sagittal
and transverse views so not to and transverse views so not to mistake a muscle for mistake a muscle for parathyroid!parathyroid!
Enlarged glands have Enlarged glands have decreased echo texture and decreased echo texture and appear elongated masses appear elongated masses between the posterior longus between the posterior longus coli and the anterior thyroid coli and the anterior thyroid lobe.lobe.
Parathyroid PathologyParathyroid Pathology Primary HyperparathyroidismPrimary Hyperparathyroidism
Increased function of parathyroid glandIncreased function of parathyroid gland
AdenomasAdenomas Most common cause of primary hyperparathyroidismMost common cause of primary hyperparathyroidism Benign and usually less than 3 cmBenign and usually less than 3 cm
CarcinomaCarcinoma Most small, irregular, & firm; may adhere to surrounding Most small, irregular, & firm; may adhere to surrounding
structures. structures.
Secondary HyperparathyroidismSecondary Hyperparathyroidism Chronic hypocalcemia Chronic hypocalcemia
renal failure, vitamin D deficiency, or malabsorption syndromesrenal failure, vitamin D deficiency, or malabsorption syndromes PTH secretion to compensate for renal insufficiency and PTH secretion to compensate for renal insufficiency and
intestinal malabsorption.intestinal malabsorption.
Neck MassesNeck MassesThyroglassal Duct CystThyroglassal Duct Cyst
Congenital anomaly Congenital anomaly Midline & anterior to Midline & anterior to
trachea trachea Remnant of tubular dev’t Remnant of tubular dev’t
of thyroid gland persisting of thyroid gland persisting between the base of the between the base of the tongue and the hyoid tongue and the hyoid bonebone
Clinical SignsClinical Signs Palpable midline massPalpable midline mass Pain associated with Pain associated with
hemorrhage or infectionhemorrhage or infection Sonographic FindingsSonographic Findings
Cystic mass in the midline Cystic mass in the midline anterior to the tracheaanterior to the trachea
Internal echoes caused by Internal echoes caused by hemorrhage or infectionhemorrhage or infection
Oval, sphericalOval, spherical
Brachial Cleft Brachial Cleft CystCyst
Anterior to CCAAnterior to CCA Along the border of the Along the border of the
sternocleidomastoid sternocleidomastoid musclemuscle
Definite separation from Definite separation from the thyroid glandthe thyroid gland
Cystic HygromaCystic Hygroma
Congenital lymphatic Congenital lymphatic malformation of malformation of posterolateral neckposterolateral neck
Webbed neckWebbed neck
Sonographic FindingsSonographic Findings Thin walled, cystic Thin walled, cystic
multiloculated massmultiloculated mass
Thyroid ScanThyroid Scan
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