2. Anatomy of thyroid gland
• The thyroid is a butterfly-shaped gland that
lies inferior to the cricoid cartilage ,
approximately 4 cm below the superior notch
of the thyroid cartilage.
• It is comprised of a central isthmus (covering
the 2nd to 4th tracheal ring) and two lateral
lobes.
5. Differential diagnosis of anterior
midline neck swelling
Ludwig’s angina
Enlarged submental lymph nodes
Sublingual dermoid
Lipoma in the submental region
Thyroglossal cyst
Goitre of the thyroid isthmus & pyramidal
lobe
Retrosternal goitre
6. • Diseases of the thyroid gland invariably leads
to enlargement of the gland.
• The term GOITER is applied to any
enlargement of the thyroid gland regardless of
the cause.
13. Most patients with goitre are Euthyroid, But
goitre may be associated with thyroid
dysfunction (Thyrotoxicosis or
Hypothyroidism).
To examine the thyroid status we must have to
know the features of toxicosis and features of
hypothyroidism.
14. Clinical features of thyrotoxicosis
Symptoms Signs
Weight loss despite normal
or increased appetite
Heat intolerance,
sweating
Palpitations, tremor
Dyspnoea, fatigue
Irritability, emotional
lability
Weight loss
Tremor
Palmar erythema
Sinus tachycardia
Lid retraction, lid lag
Common
15. Clinical features of thyrotoxicosis
Symptoms Signs
Amenorrhoea
Spontaneous abortion
Osteoporosis
Diarrhoea, steatorrhoea
Anxiety, psychosis
Muscle weakness
Angina
Ankle swelling
Goitre with bruit
Atrial fibrillation
Systolic hypertension
increased pulse pressure
Cardiac failure
Hyper reflexia
Proximal myopathy
Less Common
16. Clinical features of hypothyroidism
Symptoms Signs
Weight gain
Cold intolerance
Dry skin
Dry hair
Fatigue, somnolence
Menorrhagia
Weight gain
Common
17. Clinical features of hypothyroidism
Symptoms Signs
Constipation
Hoarseness
Depression
Deafness
Infertility
Muscle stiffness
Alopecia
Aches and pains
Hoarse voice
Loss of lateral eyebrows
Anaemia
Carotenaemia
Delayed relaxation of
reflexes
Dermal myxedema
Bradycardia
hypertension
Less Common
18. Clinical features of thyroid
neoplasm
• Solitary thyroid nodule
• Cervical lymphadenopathy
• Rapidly enlarging goitre
• Pain in the neck
• Stridor due to tracheal compression
• Dysphagia due to esophageal
compression
• Hoarseness due to vocal cord palsy
20. History
To see the thyroid status of the patient we
must have to ask about the History
suggesting thyrotoxicosis or hypothyroidism.
21. Past medical, drug, family and social
history
Prior neck irradiation
Recent pregnancy
Drug therapy
Family history of thyroid or other autoimmune
disease.
22. Residence in an area of iodine deficiency,in
bangladesh certain northern districts,
particularly rangpur, gaibandha, nilphamari,
and dinajpur are considered as goiter-prone
areas.
Smoking (increases the risk of graves’
opthalmopathy)
24. Observe the facial appearance, noting signs
of dry or coarse hair and periorbital
puffiness.
Inspect the hands for vitiligo, thyroid
acropachy, onycholysis and palmar
erythema.
Assess pulse (tachycardia, atrial fibrillation,
bradycardia) and blood pressure.
25. Auscultate the heart for a mid systolic flow
murmur(hyperthyroidism).
Inspect the limbs for coarse, dry skin and
pretibial myxedema.
Assess proximal muscle power and deep
tendon (ankle) reflexes.
31. Inspection
Inspect the neck from the front; note the
position, diffuse or localised nature of
swelling, extent, shape, size, overlying skin
(dilated veins, thyroidectomy scar, local signs
of inflammation) of the swelling.
32. Inspect the thyroid from the side with the
patient’s neck slightly extended.
33. Give the patient a glass of water and ask
them to take a sip and then swallow.
As Thyroid swelling moves upwards on
swallowing, look for the inferior border as
soon as the gland moves up.
34. Palpation
At first, palpation of the thyroid gland should
always be done from the behind on a sitting
patient by using both hands with slight flexion of
the neck ( to relax the sterno mastoid muscles)
and thumbs placed over the nape of the neck.
35. Ask the patient to swallow again and feel the
gland as it moves upward.
Note the size, shape, surface, mobility,
tenderness and consistency of any goitre and
feel for any thrill.
Palpate the cervical lymph nodes.
36. a) Size – small or large
b) Shape – localised or diffuse
swelling, nodular (single or
multiple) or not.
c) Surface – smooth or irregular
d) Consistency -
• Soft – normal gland, Cystic
swelling, graves disease.
• Firm – simple goitre
• Hard – carcinoma of thyroid
• Woody feel – reidel’s thyroiditis
37. e) Mobility – fixed or mobile. Mobility is lost in
carcinoma of thyroid with infiltration.
f) Tenderness – tender
(thyroiditis, malignancy, bleeding within cyst) or
non tender
g) Thrill – present in graves disease due to
increased vascularity.
41. Investigation Indication/comment
Biochemistry
Thyroid function test To assess thyroid status
Immunology
Antithyroid
peroxidase
antibodies
Non-specific, high in
autoimmune thyroid
disease
Antithyroid
stimulating hormone
receptor antibodies
Specific for graves
disease
42. Investigation Indication/comment
Imaging
Ultrasound
Thyroid scintigraphy
Computed tomography
Goitre, nodule
To assess areas of hyper-
/hypoactivity
To assess goitre size and
aid surgical planning
Invasive / other
Respiratory flow
volume loop
Thyroid nodule Fine needle
aspiration cytoloogy
To assess tracheal
compression from a
large goitre
44. THYROTOXICOSIS
Toxic Multinodular
goitre
Toxic
adenoma
1. Drugs – Carbimazole
And Propylthiouracil.
2. Radioiodine therapy
3. Surgery
1. Beta blocker
2.Radio iodine therapy
3.Surgery (occasionally
necessary, if there is
large goitre)
Radio iodine
therapy or
surgery
45. Paillary Carcinoma
And Follicular
Carcinoma
Anaplastic or
undifferentiated
carcinoma
Medullary
carcinoma
1. Total thyroidectomy
followed by high dose
Radio Iodine Therapy
2. Life long T4 (to
suppress TSH,if it is
TSH dependent)
There is no effective
treatment for
anaplastic
carcinoma,although
surgery and
radiotherapy may be
considered in some
circumstances.
Total thyroidectomy
with removal of
affected lymph nodes
and T4 therapy.
External radiotherapy
may be given after
surgery.
It has outer false capsule derived from pretracheal fascia, and inner true capsule of loose connective tissue.
True capsule extend septa which divide it into many lobule.
Each lobule contain numerous thyroid follicle lined by simple cuboidal to columnar cell.
Parafollicular cell found between follicular cells.
Production of T3 and T4 in the thyroid is stimulated by thyroid stimulating hormone which is released from the thyrotroph cells of the anterior pituitary in response to the hypothalamic tripeptide, thyrotrophin releasing hormone.
There is a negative feedback of thyroid hormone on the hypothalamus and pituitary – TSH secretion is suppressed when plasma concentration of T3 and T4 are raised.
There is a broad differential diagnosis of anterior mid line neck swellings, which includes lymphadenopathy, dermoid cyst, Thyroglossal duct cyst.
There are numerous causes of thyroid swelling, but broadly speaking, a thyroid swelling is either a solitary nodule, a multinodular goitre, or a diffuse goitre.
Patients with thyroid tumors usually present with a solitary nodule. Only 5-10% of thyroid nodules are malignant.
A solitary nodule presenting in childhood or adolescence or one presenting in the elderly should heighten suspicion of a primary thyroid malignancy.
Most thyroid tumors are benign , called follicular adenoma or papillary adenoma. A few of these called toxic adenoma, which secret excess thyroid hormone.
Malignant tumors of thyroid can be classified according to the cell type of origin.
1.Papillary carcinoma is slowly growing tumor , arises from follicular cells of thyroid.
Young adults are affected more, in between 20-40 years of age
Females are 3 times more affected than Male
Papillary carcinoma Consist 75 - 85% of total thyroid malignancy
Lymphatic spread is common(level 3-7), patient may present with cervical lymphadenopathy.
2.Follicular Carcinoma is always a single encapsulated lesion.
common in middle aged, between 40 to 60 years .
Blood born metastases are common ,usually to bones, brain and lungs .
3.Patients with anaplastic carcinoma and lymphoma are usually over 60 years of age and present with rapid thyroid enlargement over 2-3 months. Anaplastic carcinoma is Locally infiltrative & invade surrounding structure ,Spread by lymphatic's and by blood stream . The goitre is hard and there may be stridor due to tracheal compression and hoarseness due to recurrent laryngeal nerve palsy. In older patients with anaplastic carcinoma median survival is only 7 month.
Most lymphoma Occur against a background of lymphocytic thyroiditis.
High grade Non –Hodgkin’s B-cell lymphoma are common type.
4.Medullary carcinoma arises from parafollicular C cells of the thyroid. Patient usually present in middle age with a firm thyroid mass. Cervical lymph node involvement is common but distant metastases are rare initially.
thyroid swelling patient may present with features of thyrotoxicosis.
Common presenting symptoms of thyrotoxicosis include…..
Most common signs in patient with thyrotoxicosis include…….
thyroid swelling patient may present with features of hypothyroidism.
Common presenting symptoms of hypothyroidism include…..
Most common signs in patient with hypothyroidism include…….
thyroid swelling patient may present with features of hypothyroidism.
Common presenting symptoms of hypothyroidism include…..
Most common signs in patient with hypothyroidism include…….
Ask about…..
Ask about Prior neck irradiation which is a risk factor for thyroid malignancy
Ask about Recent pregnancy as postpartum thyroiditis usually occurs in the first 12 months
History of drug therapy is important as anti thyroid drugs or radio iodine therapy ; amiodarone and lithium can cause thyroid dysfunction.
Family history of thyroid or other autoimmune disease.
Picture shows a patient with overactive thyroid,There is bilateral exophthalmos. Patient looks anxious and restless.
Picture shows a hypothyroid patient whose thyroid gland is enlarged and his appearance is immobile and uninterested.
This picture shows Thyroid acropachy which is present only in graves disease.
Patient with thyrotoxicosis may present with onycholysis.
Extending the neck will cause the thyroid to rise by a few centimeters and may make the gland more apparent.
To confirm the neck swelling as goitre give…..
Changing the percussion note from resonant to dull indicates the possibility of retrosternal goitre.
Ask the patient to hold his breath and then auscultate. Search for systolic bruit over the lateral lobes of the thyroid gland.
To assess thyroid status Free T3 and free T4, Thyroid stimulating Hormone(TSH) are now measured.
Antibody against TSH receptor presents in Graves‘ Disease.
Ulltrasonography of the Thyroid gland :
High sensitivity for determining the physical characteristics of the thyroid swelling and demonstrate sub-clinical nodularity and cyst formation
But low specificity for the differentiation between benign and malignant lesion.
Isotope scan
Uptake scanning is done by either by radiolabelled I123 or by the technetium (99mTc).Routine isotope scanning is unnecessary.
It’s principle value is in the toxic patient with a nodule.
One scanning - swelling are categorized as
Hot (overacting)
Warm (active) or
Cold (underactive)
CT scan and MRI
Not use as a routine or First line investigations.
Reserved for the assessment of known Malignancy, to assess the extension of retrosternal and recurrent goitre & nodal metastases.
Fine needle aspiration Cytology(FNAC)
Provide most direct and specific information about the pathology of thyroid nodules.
Ultrasonography guided FNAC give more accurate results.
It’s sensitivity 65-90% and specificity is 72-100%.
FNAC has excellent patient compliance, is simple and quick to perform in out patient department .
Three modes of treatment of thyrotoxicosis : drugs, radioiodine therapy, surgery.
Indication of surgery in thyrotoxicosis is large goitre with pressure effect, relapse or no response to drugs, cosmetic purpose and suspicion of malignancy.
Anti thyroid drugs are given for short time in toxic Multinodular goitre. Long term treatment with anti thyroid drugs is not helpful, as many nodules are autonomous and relapse is invariable after withdrawal of the drug. Betablocker is given to reduce the heart rate.radio iodine therapy is the treatment of choice. Surgery is oaccasionally needed.