Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 56 Thyroid Gland PPT-Powerpoint Presentations and lecture notes
THYROID GLAND
LEARNING OBJECTIVES
To understand:
? The development and anatomy of the thyroid
glands.
? The physiology and investigation of thyroid
function.
? The treatment of thyrotoxicosis and thyroid
failure.
The indications for and technique of thyroid
surgery
? The management of thyroid cancer
Mention the causes of Thyrotoxicosis. Discuss the
clinical features and management of primary
thyrotoxicosis.
Classify thyroid neoplasms. Discuss the management of
solitary thyroid nodule.
Describe how wil you proceed with the diagnosis and
treatment of a 40 y old female with multinodular goitre.
Discuss the etiology, clinical features, diagnosis and
treatment of MNG.
Discuss the etio pathology,clinical features, diagnosis
and treatment of Grave's disease.
Discuss the classification and clinical features of
thyroiditis.
Discuss the etio pathology,clinical features, diagnosis
and treatment of thyroid malignancies.
SHORT NOTES
Complications of thyroid surgery.
Development of thyroid and anomalies.
Ectopic thyroid
Eye signs in Grave's disease
Jod Basedow thyrotoxicosis
MEN syndrome
Thyroglossal cyst/fistula
Thyroid storm
CLINICAL ANATOMY
VASCULAR SUPPLY
LYMPHATIC DRAINAGE
Most important when considering surgical treatment
of thyroid carcinoma.
Paratracheal nodes; tracheoesophageal groove lymph
nodes; mediastinal nodes in the anterior and superior
position; jugular lymph nodes in the upper, middle,
and lower distribution; and retropharyngeal and
esophageal lymph nodes.
Laterally, cervical lymph nodes within the posterior
triangle.
Papillary carcinoma of the thyroid is commonly
associated with adjacent nodal metastasis.
Medullary carcinoma has a strong predilection for
metastatic lymphatic involvement, usually within the
central compartment (the space between the internal
jugular veins).
RELATIONS
The gland is enclosed in the pretracheal fascia,
covered by the strap muscles and overlapped by the
sternocleidomastoids.
The anterior jugular veins course over the isthmus.
On the deep aspect of the thyroid lie the larynx and
trachea, with the pharynx and oesophagus behind and
the carotid sheath on either side.
Two nerves lie in close relationship to the gland; in
the groove between the trachea and oesophagus lies
the recurrent laryngeal nerve and deep to the upper
pole lies the external branch of the superior laryngeal
nerve passing to the cricothyroid muscle.
PHYSIOLOGY
IODIDE TRAPPING.
OXIDATION to iodine by thyroid peroxidase.
IODINATION of tyrosine residues to mono
and di iodotyrosine.
COUPLING.
HORMONE SYNTHESIS
PHYSIOLOGY
TRH secreted by hypothalamus.
Stimulates TSH secreted by ant pituitary.
Stimulates the thyroid gland to synthesise
T3 and T4.
T3 and T4 have negative feedback inhibition
on TSH and TRH.
PHYSIOLOGY
The thyroid hormones secreted by the gland
are in bound form and free form.
Free form is biologically active.
The hormones once liberated are bound to
serum proteins- name?
T3 has a rapid onset of action and a much
shorter half life than T4.
Thyroid hormone synthesis is inhibited by?
CONGENITAL DISEASES
DEVELOPMENT
The thyroid develops
from a bud which
pushes out from the
floor of the pharynx
and then descends to
its definitive position
in the neck.
THYROGLOSSAL CYST
LINGUAL THYROID
Occurs as a failure of normal descent of the thyroid
Presents as a lump in the foramen caecum or in the front
of the neck near the body of the hyoid bone.
In all cases of unexplained nodules in the line of thyroid
descent, a radio-iodine scan should be performed to
ensure that there is normal thyroid tissue in the correct
place before the lump is removed.
Enlargement of a lingual thyroid can cause airway
obstruction, dysphagia, or bleeding.
Most lingual thyroid glands can be suppressed with
thyroid hormone administration.
In resistant lingual thyroids, radioactive iodine treatment
may be given.
ECTOPIC THYROID TISSUE
Can be found in the central compartment of the
neck, under the lower poles of normal thyroid or in
the anterior mediastinum.
Lateral aberrant thyroid
PENDRED'S SYNDROME
A rare autosomal recessive condition
characterised by incomplete oxidation of
trapped iodide prior to organification.
Associated with sensorineural deafness,
mild primary hypothyroidism with a non-toxic
diffuse goitre.
It may be confirmed by a positive
perchlorate discharge test.
TESTS OF THYROID FUNCTION
EVALUATION OF PITUITARY- THYROID
FEEDBACK LOOP
1)Serum TSH assay
2)TRH stimulation test
SERUM T3 AND T4 LEVELS
Only a small fraction of the total (0.03% of
T4 and 0.3% of T3) is free.
Assays of total hormones are now obsolete.
Estimation of free T3 and free T4.
T3 resin uptake test
THYROID AUTOANTIBODIES
TPO antibodies
Anti thyroglobulin antibodies
Antimicrosomal antibodies
THYROID IMAGING
1) Chest X-Ray.
THYROID IMAGING
USG
Helps in determining
the nature of swelling.
USG guided FNAC.
Helps in detecting
MetastaticLNs.
Followup.
THYROID IMAGING
CT scan
To know the extent of
malignancy and
reterosternal extension.
THYROID SCINTIGRAPHY
Provide information about thyroid activity , the size and
extent of the gland.
Helpful in showing retrosternal extension.
Material used is Tc 99m, I123,I131.
Cold nodule: 80% benign,20% malignant.
Hot nodule: 5-9% malignant.
Warm nodule: take up the same radioactivity as rest of
the gland.
The principal benefits of isotope scanning are in
confirming the presence of a `hot/toxic' nodule in the
thyroid gland in a thyrotoxic patient, and in identifying
metastases or residual local disease after total
thyroidectomy for carcinoma.
THYROID SCINTIGRAPHY
A hot nodule is one that takes up isotope while the
surrounding thyroid tissue does not.
Here, the surrounding thyroid tissue is inactive
because the nodule is producing such high levels of
thyroid hormones that TSH secretion is suppressed.
A warm nodule takes up isotope, as does the
normal thyroid tissue around it.
A cold nodule does not take up isotope
FNAC
IOC for discrete thyroid swellings.
Thy1- Non-diagnostic
Thy2- Non-neoplastic
Thy3 -Follicular
Thy4 -Suspicious of malignancy
Thy5- Malignant
MISCELLANEOUS
Serum calcitonin
Serum thyroglobulin-concentrations > 50g/l indicate
probable residual or recurrent tumour.
Concentrations >100 g/l strongly suggest the
presence of pulmonary or skeletal metastases.
Flow cytometry for identifying diploid tumours, which
have a good prognosis, and aneuploid tumours,
which have a poor prognosis.
CLINICAL FEATURES
There are two broad categories of symptoms :
those occurring as a result of the enlargement of
the gland itself and those related to its disordered
endocrine activity.
The history will establish whether one or both
classes of symptoms are present, and examination
then aims to elicit the relevant physical signs.
NECK SYMPTOMS
A lump in the neck
Discomfort on swallowing
Dyspnoea
Hoarseness
HYPOTHYROIDISM
ADULT (MYXEDEMA)
? Hypothyroidism in adults THs.
? Could be:
1ry hypothyroidism ... (diseases is in the gland)
- autoimmune disease such as "Hashimoto's thyroiditis".
- lack of iodine.
- absence of deiodination enzyme.
T3 & T4 reflex TSH.
2ry hypothyroidism ... (disease is higher up)
TRH TSH T3 & T4.
? Follicular cells become less active.
HYPOTHYROIDISM
Autoimmune thyroiditis (chronic lymphocytic
thyroiditis)
Non-goitrous: Primary myxoedema
Goitrous: Hashimoto's disease
Iatrogenic
After thyroidectomy
After radioiodine therapy
Drug induced (anti-thyroid drugs, para-aminosalicylic
acid,Amiodarone,Cytokines and iodides in excess)
Dyshormonogenesis
Goitrogens
Secondary to pituitary or hypothalamic disease
Thyroid agenesis
Endemic cretinism---- due to iodine deficiency
CRETENISM
Inadequate thyroid hormone production during fetal
and neonatal development.
2 types- Endemic and Sporadic
A hoarse cry, macroglossia and umbilical hernia in
a neonate with features of thyroid failure suggests
the diagnosis.
Tt is by thyroxine.
ADULT HYPOTHYROIDISM
The symptoms are:
The signs are:
? tiredness;
? bradycardia;
? mental lethargy;
? cold extremities;
? cold intolerance;
? dry skin and hair;
? weight gain;
? periorbital puffiness;
? constipation;
? hoarse voice;
? menstrual disturbance;
? bradykinesis, slow
? carpal tunnel syndrome
movements;
? delayed relaxation
phase of ankle jerks
MYXEDEMA
The signs and symptoms
of hypothyroidism are
accentuated.
The facial appearance is
typical-supraclavicular
puffiness, a malar flush
and a yellow tinge to the
skin.
Myxoedema coma,
characterised by altered
mental state, hypothermia
and a precipitating
medical condition, for
example cardiac failure or
infection.
DIAGNOSIS AND TREATMENT
Low T4 and T3 levels with a high TSH.
What will happen in Pituitary failure?
High serum levels of TPO antibodies are
characteristic of autoimmune disease.
Treatment-
Oral thyroxine (0.10?0.20 mg) as a single daily
dose.
THYROTOXICOSIS
Describe the causes
Discuss the pros and cons of the three major treatment
options
Know how to prepare a patient for operation
Describe appropriate surgical procedures
Know about early and late postoperative management
THYROTOXICOSIS
THYROTOXICOSIS v/s HYPERTHYROIDISM??
Hyperthyroidism is a condition in which the thyroid
gland producesand secretes excessive amounts of
the free thyroid hormones.
Thyrotoxicosis
hypermetabolic clinical syndrome which occurs
when there are elevated serum levels of T3 and/or
T4.
Thyrotoxicosis can also occur without
hyperthyroidism.
THYROTOXICOSIS
Clinical types are:
? diffuse toxic goitre (Graves' disease);
? toxic nodular goitre;
? toxic nodule;
? hyperthyroidism due to rarer causes.
THYROTOXICOSIS
Diffuse toxic goitre
Graves' disease, occurs in younger women .
Associated with eye signs.
50% of patients have a family history of
autoimmune endocrine diseases.
The whole of the functioning thyroid tissue is
involved.
Hypertrophy and hyperplasia are due to abnormal
thyroid-stimulating antibodies (TSH-RAbs)
THYROTOXICOSIS
Toxic nodular goitre
A simple nodular goitre is present for a long time
before the Hyperthyroidism.
Middle-aged or elderly.
Very infrequently associated with eye signs.
The syndrome is that of secondary thyrotoxicosis.
In many cases of toxic nodular goitre the nodules
are inactive and it is the internodular thyroid tissue
that is overactive.
THYROTOXICOSIS
Toxic nodule
A toxic nodule is a solitary overactive nodule, which
may be part of a generalised nodularity or a true
toxic adenoma.
It is autonomous and its hypertrophy and
hyperplasia are not due to TSH-RAb.
TSH secretion is suppressed by the high level of
circulating thyroid hormones and the normal thyroid
tissue surrounding the nodule is itself suppressed
and inactive.
THYROTOXICOSIS-CLINICAL FEATURES
The symptoms are:
The signs are:
? tiredness;
? tachycardia;
? emotional lability;
? hot, moist palms;
v ? heat intolerance;
? exophthalmos;
? weight loss;
? lid lag/retraction;
? excessive
? agitation;
appetite;
? thyroid goitre and
? palpitations.
bruit.
GRAVE'S OPHTHALMOPATHY
2 clinical phases:
The inflammatory stage and the fibrotic stage
The inflammatory stage is marked by edema and
deposition of glycosaminoglycan in the extraocular
muscles. There is orbital swelling, stare, diplopia,
periorbital edema, and at times, pain.
The fibrotic stage is a convalescent phase and may
result in further diplopia and lid retraction. It
improves spontaneously in 64% of patients
PRETIBIAL MYXEDEMA
Elevated, firm, nonpitting, localized thickening over the
lateral aspect of the lower leg, with bilateral involvement.
Milder cases do not require therapy other than treatment
of the thyrotoxicosis.
Therapy with topical steroids applied under an occlusive
plastic dressing film for 3-10 weeks has been helpful.
In severe cases, pulse glucocorticoid therapy may be
tried.
ACROPACHY
Clubbing of fingers with osteoarthropathy,
including periosteal new bone formation, may
occur.
This almost always occurs in association with
ophthalmopathy and dermopathy.
No therapy has been proven to be effective.
WORKUP
TSH levels usually are suppressed to immeasurable
levels (<0.05 ?IU/mL) in thyrotoxicosis.
Subclinical hyperthyroidism is defined as a
suppressed TSH level (<0.5 U/mL in many
laboratories) in combination with serum
concentrations of T3 and T4 that are within the
reference range.
Thyroid autoantibodies: The most specific
autoantibody for autoimmune thyroiditis is an
enzyme-linked immunosorbent assay (ELISA) for
anti-TPO antibody (thyroperoxidase).
SCANNING
Graves disease is associated with diffuse enlargement
of both thyroid lobes, with an elevated uptake .
A toxic multinodular goiter demonstrates an enlarged
thyroid with multiple nodules and areas of both
increased and decreased isotope uptake .
Subacute thyroiditis usually demonstrates very low I-123
isotope uptake.
A toxic adenoma demonstrates a solitary hot nodule
with suppression of function in the surrounding normal
thyroid tissue .
MANAGEMENT
ANTITHYROID DRUGS
SURGERY
RADIOIODINE
ANTI THYROID DRUGS
Carbimazole, methimazole and propylthiouracil
are most commonly used.
Reduce the synthesis of thyroid hormones by
inhibiting the iodination of tyrosine residues.
Carbimazole also has an immunosuppresive
action.
Clinical improvement occurs within 10-14 days.
Pt is clinical y and biochemical y euthyroid by 3-
4 wks.
Tt is continued for 12-18 months.
ANTI THYROID DRUGS
ADVANTAGE
No surgery and no use of radioiodine.
q DISADVANTAGE
Tt is prolonged and the failure rate is atleast 50%
Some goitres enlarge and become more vascular
during tt.
Side effects are agranulocytosis or aplastic anemia
SURGERY
Usually done when there is a large goitre,poor drug
compliance,recurrence.
Subtotal thyroidectomy is done.
Contraindication is previous thyroid surgery.
Complications are hypothyroidism,transient
hypocalcemia,permanent
hypoparathyroidism,recurrent laryngeal nerve palsy.
SURGERY
ADVANTAGE
Goitre is removed.
Cure is rapid and cure rate is high.
? DISADVANTAGE
Recurrenc occurs in 5%
Every operation carries mortality and morbidity.
Post op thyroid insufficiency
RADIOIODINE
131I is given orally as a single dose and is
trapped and organified in thyroid.
There is alag period of 4-12 wks before it is
effective.
During this period the symptoms are
controlled by beta blockers.
Contraindications are pregnancy,active
graves ophthalmopathy.
Complications are
hypothyroidism,malignancies of thyroid and
gi tract.
RADIOIODINE
No surgery and prolonged drugs.
DISADVANTAGE
Isotope facilities must be available.
High incidence of hypothyroidism which may reach 75
-80% after 10 yrs.
Indefinite follow up.
Increased risk of malignancy.
CHOICE
1.DIFFUSE TOXIC GOITRE-
Over 45-Radioiodine
Under 45-Surgery for large goitre and drugs for small
goitre.
2.TOXIC NODULAR GOITRE-
SURGERY.
3.TOXIC NODULE-
Surgery or Radioiodine
4.RECURRENT THYROTOXICOSIS AFTER
SURGERY-
Over 45-Radioiodine,Under 45-Drugs.
Correction of hyperthyroidism is important for the
ophthalmopathy.
Antithyroid drugs and thyroidectomy do not
influence the course of the ophthalmopathy,
whereas radioiodine treatment may exacerbate
preexisting ophthalmopathy but can be prevented
by glucocorticoids.
In the long term, thyroid ablation may be beneficial
for ophthalmopathy because of the decrease in
antigens shared by the thyroid and the orbit in the
autoimmune reactions.
GRAVE'S OPHTAHLMOPATHY
For mild-to-moderate ophthalmopathy, local therapeutic
measures (eg, artificial tears and ointments, sunglasses,
eye patches, nocturnal taping of the eyes, prisms,
elevating the head at night) can control symptoms and
signs.
If the disease is active (1) high-dose glucocorticoids, (2)
orbital radiotherapy, (3) both, or (4) orbital
decompression
PRE OP PREPARATION
Carbimazole in the dose of 30-40mg daily for 8-
12wks is given. when euthyroid the dose is reduced
to 5mg t.d.s.
Iodides in the form of lugol's iodine is used 2-3 wks
prior to surgery.dose is 30 drops t.d.s.it reduces the
size and vascularity of the gland.
Propranol acts on the target organs and not on the
gland itself. Dose is 40mgt.d.s.it inhibits the
peripheral conversion of T4 to T3.
POSTOPERATIVE COMPLICATIONS
Haemorrhage
Respiratory obstruction
Recurrent laryngeal nerve paralysis and voice
change
Thyroid insufficiency
Parathyroid insufficiency
Thyrotoxic crisis
Wound infection
Hypertrophic or keloid scar
Stitch granuloma
GOITRE
Know how to describe thyroid swellings
Use appropriate investigations
Know the indications for surgery
Select the appropriate procedure
Describe and manage postoperative complications
CLASSIFICATION OF GOITRE
Simple goitre (euthyroid)
Diffuse hyperplastic
Physiological
Pubertal
Pregnancy
Multinodular goitre
Toxic
Diffuse
Graves' disease
Multinodular
Toxic adenoma
Neoplastic
Benign
Malignant
CLASSIFICATION OF GOITRE
Inflammatory
Autoimmune
Chronic lymphocytic thyroiditis
Hashimoto's disease
Granulomatous
De Quervain's thyroiditis
Fibrosing
Riedel's thyroiditis
Infective
Acute (bacterial thyroiditis, viral thyroiditis, `subacute
thyroiditis')
Chronic (tuberculous, syphilitic)
Inflammato Hyperplasi
Tumours
Others
ry
a
Benign
Malignant
Graves
Multinodular Follicular
Papillary Colloid cyst
Disease
goitre
adenoma
Hashimoto's Non-toxic
Follicular
Thyroid
thyroiditis
goitre
lymphoma
De
Anaplastic
Acute
Quervain's
suppurative
thyroiditis
Medullary
SIMPLE GOITRE
Stimulation of the thyroid gland by TSH.
The most common cause iodine deficiency.
Increased demand.
Excess iodine or lithium ingestion, which
decrease release of thyroid hormone
Goitrogens(cassava, lima beans, maize, bamboo
shoots, and sweet potatoes)
-Inborn errors of metabolism causing defects in
biosynthesis of thyroid hormones
- Exposure to radiation
-Thyroid hormone resistance
Side-effects of pharmacological therapy
such as:
Amiodarone :
inhibits peripheral conversion of thyroxine to
triiodothyronine; also interferes with
thyroid hormone action.
Phenobarbitone, phenytoin, carbamazepine,
Rifampcin:
induce metabolic degradation of T3 and T4.
? If No Iodine T3 & T4 TRH TSH
growth (size) of the gland simple goiter.
HOW GOITER IS FORMED?
WITH LACK OF IODINE ...
Hypothalamus
COLD
TR
+
H
Anterior
pituitary
TS
+
NO or low
H
Thyroi
Lack of
feedback
iodine
inhibition
d gland
Poo
+++
r
Low T3 or T4
Growth of
release
the gland
NATURAL HISTORY
Persistant growth stimulation cause diffuse
hyperplasia ,all lobules are composed of
active follicles and iodine uptake is uniform
.This is a diffuse hyperplastic goiter .
Mixed pattern develops with areas of active
lobules and areas of inactive lobule as a
result of fluctuating stimulation.
Active lobules become more vascular &
hyperplastic untill haemorrhage occur
causing central necrosis & leaving only a
surrounding rind of active follices.
Necrotic lobules __
form nodules filled with
either iodine-free colloid
or a mass of new but
inactive follicles.
Continual repetition
of this process result
in a nodular goiter.
CLINICAL FEATURES
Euthyroid.
Neck swelling which moves on swallowing.
Rule out compressive symptoms.
Hardness and irregularity, due to calcification, may
simulate carcinoma.
A painful nodule or the sudden appearance or rapid
enlargement of a nodule may be because of
haemorrhage or carcinoma.
INVESTIGATIONS
Serum TSH.
USG neck.
Thyroid autoantibodies.
Plain X-Ray neck.
FNAC.
COMPLICATIONS
Respiratory obstruction.
Secondary Thyrotoxicosis.
Carcinoma (Follicular).
PREVENTION AND TREATMENT OF SIMPLE
GOITRE
Iodised salt.
INDICATIONS OF SURGERY:
Cosmesis
Retrosternal extension.
Compressive symptoms.
Suspected malignancy.
WHAT SURGERY???
Total thyroidectomy
Subtotal thyroidectomy leaving up to 4 g of
relatively normal tissue in each remnant.
Total lobectomy on the more affected side with either
subtotal resection (Dunhill procedure) or no intervention
on the less affected side.
DISCRETE THYROID SWELLING
WHAT IS SOLITARY SWELLING OF THYROID?
WHAT IS DOMINANT SWELLING?
About 70% of discrete thyroid swellings are
isolated and about 30% are dominant.
The importance lies in the increased risk of
neoplasia compared with other thyroid swellings.
15% of isolated swellings are malignant, 30?40%
are follicular adenomas.
CLINICALLY DISCRETE SWELLINGS
What are the risk factors which suggest that a
discrete swelling is malignant????
When will you suspect malignancy in a discrete
swelling????
CLINICALLY DISCRETE SWELLINGS
Causes???
Investigation???
CLINICALLY DISCRETE SWELLINGS
INDICATIONS OF SURGERY?
All proven malignant nodules.
Cytologically proven follicular adenoma.
Suspicious nodules.
Cystic nodules which recur following aspiration.
Nodules producing obstructive symptoms.
Toxic nodule.
Cosmesis.
Patient's wish.
RETROSTERNAL GOITRE
RETROSTERNAL GOITRE
Arise from the lower pole of a nodular goitre.
Short neck and strong pretracheal muscles incresase
the negative intrathoracic pressure which tends to draw
these nodules into the superior mediastinum.
Symptomless.
Dyspnoea, particularly at night,
Cough and stridor
Dysphagia.
Engorgement of facial, neck and superficial chest wall
veins.
Obstruction of the superior vena cava
Recurrent nerve paralysis
RETROSTERNAL GOITRE
CXR
CT Scan.
Surgery.
THYROID INCIDENTALOMA
THYROID INCIDENTALOMA
Due to the increased use of imaging modalities for
non-thyroid head and neck pathology.
Clinically unsuspected and impalpable thyroid
swellings.
Generates needless anxiety.
Can be safely managed expectantly by a single
annual review.
Thyroid incidentaloma
on US, MRI or CT scan
Greater than 1.5 cm
radiation exposure
Less than 1.5 cm
US, MRI or CT ?cancer
US, MRI or CT scan
benign
FH thyroid cancer
US guided
FNAC
Observe
HASHIMOTO'S THYROIDITIS
Characterized by the destruction of thyroid cells by
cell- and antibody-mediated immune processes.
The thyroid gland is typically goitrous.
Antithyroid peroxidase (anti-TPO), antithyroglobulin
(anti-Tg),TSH receptor-blocking antibodies.
Inadequate thyroid hormone production and
secretion.
Initially, (T4) and (T3) may "leak" into the circulation
from damaged cells.
10-15 times more common in females.
The most commonly affected age range is 30-50
years.
WORKUP
TFT.
USG.
Complete blood count.
Total and fractionated lipid profile.
WORKUP
Basic metabolic panel: Glomerular filtration rate, renal
plasma flow, and renal free water clearance are all
decreased in hypothyroidism and may result in
hyponatremia.
Creatine kinase: Creatine kinase levels, predominantly
the MM isoenzyme from skeletal muscle and the
aldolase enzyme, are frequently elevated in severe
hypothyroidism.
Prolactin: Prolactin may be elevated in primary
hypothyroidism
TREATMENT
The treatment of choice for Hashimoto thyroiditis is
thyroid hormone replacement.
The drug of choice is orally administered
levothyroxine sodium, usually for life.
Indications for surgery
A large goiter with obstructive symptoms such as
dysphagia, voice hoarseness, and stridor from extrinsic
obstruction to airflow.
Presence of a malignant nodule, as found by cytologic
examination by fine-needle aspiration.
Presence of a lymphoma diagnosed on fine-needle
aspiration.
Cosmetic reasons for unsightly large goiters
REIDEL'S THYROIDITIS
A rare, chronic inflammatory disease of the thyroid
gland characterized by a dense fibrosis that
replaces normal thyroid parenchyma.
The fibrotic process invades adjacent structures of
the neck and extends beyond the thyroid capsule.
This feature differentiates RT from other
inflammatory or fibrotic disorders of the thyroid.
Because of the encroachment beyond the thyroid
capsule, other problems can be associated with RT,
including hypoparathyroidism, hoarseness (due to
recurrent laryngeal involvement), and stridor (due to
tracheal compression).
PATHOPHYSIOLOGY
The etiology of Riedel's thyroiditis (RT) is unknown.
An autoimmune process or a primary fibrotic disorder.
The following evidence supports an autoimmune
pathogenesis for RT:
The presence of antithyroid antibodies in a significant
percentage of patients with RT (67% of 178 cases
reviewed in one study)2
The pathological features of cellular infiltration, including
lymphocytes, plasma cells, and histiocytes
The frequent presence of focal vasculitis on pathologic
examination
The favorable response of a subset of patients with RT
to treatment with systemic corticosteroids
CLINICAL FEATURES
History
Nonpainful, rapidly growing thyroid mass.
Hard, fixed, painless goiter- stony or woody.
Most patients are euthyroid. Hypothyroidism is
noted in approximately 30% of cases.
Local compressive symptoms.
Hypoparathyroidism.
Clinical features closely resemble those of
anaplastic carcinoma of the thyroid.
One distinguishing feature of RT is the absence of
associated cervical adenopathy.
CLINICAL FEATURES
Approximately one third of patients with RT have an
associated extracervical manifestation of multifocal
fibrosclerosis (eg, retroperitoneal fibrosis,
mediastinal fibrosis, orbital pseudotumor,
pulmonary fibrosis, sclerosing cholangitis, lacrimal
gland fibrosis, fibrosing parotitis).
MANAGEMENT
ROUTINE TESTS.
FNAC,BIOPSY.
SURGERY.
DEQUAIRVEIN'S
THYROIDITIS
Most common cause of a painful thyroid gland.
Pain in the region of the thyroid, which is usually
diffusely tender with systemic symptoms.
Hyperthyroidism occurs initially, sometimes
followed by transient hypothyroidism.
Complete recovery in weeks to months is
characteristic.
PATHOPHYSIOLOGY
A viral infection like coxsackievirus, Ebstein-Barr,
mumps, measles, adenovirus, echovirus, and
influenza.
A strong association exists with human leukocyte
antigen (HLA)-B35.
EPIDEMIOLOGY
Sex
Female-to-male ratio of 3-5:1.
Age
A peak incidence in the fourth and fifth decades
of life
HISTORY
History
Flulike prodromal episode 1-3 weeks prior to the onset of
clinical disease. The natural course of the disease can
be divided into the following 4 phases that usually unfold
over a period of 3-6 months:
The acute phase, lasting 3-6 weeks, presents primarily
with pain. Symptoms of hyperthyroidism also may be
present.
The transient asymptomatic and euthyroid phase lasts 1-
3 weeks.
The hypothyroid phase lasts from weeks to months, and
it may become permanent in 5-15% of patients.
The recovery phase is characterized by normalization of
thyroid structure and function.
S|S
Local symptoms
Pain over the thyroid that radiates to the neck, ear, jaw,
throat, or occiput; and is aggravated by swallowing and
head movement;
pain is the presenting symptom in over 90% of cases
Dysphagia
Hoarseness (uncommon)
Constitutional symptoms (often absent)
S|S
Symptoms of hyperthyroidism (palpitations,
tremulousness, heat intolerance, sweating,
nervousness) occurring in the initial phase of the
disease
Hyperthyroidism that usually is mild and rarely is severe
Transient symptoms, usually lasting 3-6 weeks
Symptoms of hypothyroidism, occurring in the late
phase of the disease
Mostly mild or moderate
Hypothyroidism lasts weeks to months
WORKUP
Usually, the diagnosis is made on clinical grounds,
and the only laboratory studies needed initially are
those to determine whether hyperthyroidism is
present, including TSH and free T4.
If any doubt exists as to whether de Quervain
thyroiditis is the correct diagnosis, 2 other tests may
be helpful.
Serum thyroglobulin is almost always markedly elevated.
Erythrocyte sedimentation rate (ESR) is usually higher
than 50 mm/h in the initial phase
WORKUP
After the initial inflammatory phase subsides, TSH
should be monitored at intervals of 4-6 weeks for a
few months to determine whether hypothyroidism
occurs.
Antibodies to TGB, thyroid peroxidase, and TSH
receptor are usually absent in de Quervain
thyroiditis.
In rare cases with systemic multiorgan involvement,
elevation of serum alkaline phosphatase, gamma-
glutamyl transpeptidase, aminotransferases, and
pancreatic enzymes may occur. Glucose
intolerance has been reported.
TT.
Management is directed towards 2 problems--pain
and thyroid dysfunction.
Pain
Some patients with mild pain require no treatment.
Nonsteroidal anti-inflammatory drugs (NSAIDs), are
used.
If pain does not respond within 3 days, the diagnosis
should be reconsidered.
TT.
Management of thyroid dysfunction
In the initial phase of de Quervain thyroiditis,
symptomatic hyperthyroidism can be treated with beta-
blockade (propranolol 10-20 mg qid or atenolol 25-50
mg/d).
If hypothyroidism occurs during the late phase, it is
usually mild and transient. If symptoms are present
or TSH is elevated, the patient needs replacement
therapy with levothyroxine
THYROID NEOPLASMS
THYROID NEOPLASMS
A.BENIGN
a.Follicular adenoma.
b.Hurthle cell adenoma.
c.Colloid adenoma.
d.Papillary adenoma.
B.MALIGNANT(Dunhill classification)
a.Differentiated
1.Papillary CA(60%)
2.Follicular CA(17%)
3.Papillofollicular CA
4.Hurthle cell CA
b.Undifferentiated
1.Anaplastic CA(13%)
C.Medullary CA(6%)
D.Malignant lymphoma(4%)
E.Secondaries.
ETIOLOGY
Radiation exposure.
MNG.
Genetic.
Hashimoto's thyroiditis.
PAPILLARY CA
Most common cancer of thyroid.
Common in females and young age group.
Woolner classification includes
i)occult primary
ii)intrathyroidal.
iii)extrathyroidal
PAPILLARY CA
PATHOLOGY
Grossly it can be soft,firm,solid or cystic.
Microscopically it contains cystic spaces with
papillary projections with psammoma
bodies,malignant cells with orphan annie eye
nuclei.
PAPILLARY CA
SPREAD
Slowly progressive tumor.
Multicentric.
Spread is via lymphatics.
PAPILLARY CA
Treatment-----
Total thyroidectomy.
Suppressive dose of L-thyroxine.
Neck dissection if LNs are positive.
PROGNOSIS is good.
PAPILLARY CA
AMES SCORING-
A-Age less than 40.
M-mets
E-extent of primary tumor
S-size less than 4cm has agood prognosis
AGES SCORING-
A-age
G-grade
E-extent
S-size
FOLLICULAR CA
Can occur de novo or in a multinodular goitre.
More aggressive tumor.
Spreads mainly by blood.
Bone secondaries are typically vascular,warm
and pulsatile.
FNAC is inconclusive.
Tt. Is total thyroidectomy.
ANAPLASTIC CA
Occurs in elderly.
Very aggressive tumor of short duration.
Stridor and hoarseness of voice.
Dysphagia.
Fixity to skin.
FNAC is diagnostic.
Tracheostomy and isthmectomy to relieve
obstruction.
Radiotherapy is tt.
Very poor prognosis.
MEDULLARY CA
Arises from parafollicular c cells which
are derived from ultimobranchial body.
Contains characterstic amyloid stroma.
Calcitonin is a useful tumor marker.
Tumor also secretes 5 HT,PGs,ACTH,and
VIP
Spreads mainly via lymphatics.
Can be sporadic,associated withMENII
syndrome or familial.
Tt. Is total thyroidectomy.
A 30 years old female pregnant in her 14 weeks
developed tremors,
insomnia, intolerance to hot weather and loss of
weight. On examination
she had tachycardia and wide pulse pressure.
a. What is the possible diagnosis
b. How would you investigate it
c. Management of the condition in view of her
pregnancy
A 35 year old housewife is suffering from TNG.
She has been advised a radioiodine scan.
Which other radionuclide scans are available?
Write two merits and two demerits of radioiodine
scan.
This post was last modified on 08 April 2022