Thyroid- Benign swellings

Benign thyroid swellings are common clinical problem. Should know about primary and secondary thyrotoxicosis.

1. THYROID- BENIGN SWELLINGS 
DR.B.SELVARAJ MS;MCH;FICS
MMMC;MALAYSIA

2.              
ANATOMY 

3.             PHYSIOLOGY 

4.      
DEFINITIONS 
•
GOITER
: any enlargement of thyroid gland

•
Thyrotoxicosis
: Symptoms of thyroid hormone excess due
to increased synthesis or release due to destructio n of
thyroid follicles or exogenous thyroid hormone
supplementation.

•
Hyperthyroidism
: Features of thyroid hormone excess due
to increased synthesis of thyroid hormone by the gl and.

5. CONDITIONS CAUSING 
THYROTOXICOSIS 
•Diffuse toxic goitre (Grave’s disease)
•Toxic nodular goitre (Toxic MNG)- Plummer’s disease
•Toxic nodule (Toxic adenoma)- Goetsch’s disease
•Thyrotoxicosis factitia (Due to excess exogenous th yroid
hormone supplementation)
•Jod-Basedow thyrotoxicosis (Iodide induced)
•Thyroiditis
•Malignancies of thyroid.
•Trophoblastic tumor (Due to thyroid stimulating act ion of
HCG produced by this tumor)
•Ectopic thyroid tissue (Struma ovarii)

6. Primary thyrotoxicosis  Secondary thyrotoxicosis 
Age 
Younger patients  Middle age and elderly 
Onset 
Goitre and Hyperthyroidism 
appear simultaneously 
Goitre present for many years prior 
to hyperthyroidism 
Symptoms 
Calorigenic (weight loss,heat 
intolerance) and nervous 
manifestations common 
Cardiovascular manifestations 
more common 
Signs 
All eye signs present. 
Diffuse goitre,highly vascular 
(bruit+) 
Only limited eye signs present 
(spastic)-lid spasm and lid lag. 
Nodular goitre 
complications 
Obstructive symptoms 
uncommon 
Obstructive symptoms commoner 
Treatment 
Start with anti thyroid 
drugs.Subsequent surgery or 
radio-iodine if needed 
Definite role for surgery 

7.          
GRAVE’S DISEASE 
 
 
 
 
•Described by Irish physician Dr.Robert Graves in 18 35

•Common in females

•Age : 20-40 years

•Pathogenesis:
•Thyroid stimulating immunoglobulins (TSI) of IgG cl ass produced
by lymphocytes stimulate TSH receptor.

•Ophthalmopathy: Fibroblast proliferation and increa sed
glycosaminoglycans production induced by TSI (?anti genic
similarity between orbital tissues and thyroid.)

8.  
CLINICAL FEATURES - SYMPTOMS 
•
Calorigenic
: Increased appetite,weight loss,heat intolerance,
increased sweating, tiredness

• Nervous
: Tremors,anxiety,nervousness,increased activity

•
CVS
: Dyspnoea, palpitations, pedal edema (due to CCF)

•
Ocular
: Diplopia, pain and increased lacrimation (due to
corneal ulcer)

9.   CLINICAL FEATURES- SYMPTOMS 
•
Menstrual
: Amenorrhoea/ oligomenorrhoea

•
Miscellaneous
: Loose stools.

10.  
 
     
THYROTOXICOSIS- SIGNS 
 
       
•
Thyroid
:Diffuse enlargement with bruit and visible
pulsations

CVS •
Pulse
: Increased sleeping pulse rate with wide pulse
pressure.
•Stages of development of thyrotoxic arrhythmias : M ultiple
extra systoles → Paroxysmal atrial tachycardia →
Paroxysmal atrial >brilla?on → Persistent AF not re sponding
to digoxin.

11.              
EYE SIGNS 
Seen in both Primary and secondary thyrotoxicosis (due to
increased thyroid hormone levels which sensitizes t he
Muller's muscle to sympathetic system)

•
Von Graefe’s sign (lid lag)
•
Stellwag’s sign
(characteristic stare with infrequent blinking)

•
Dalrymple’s sign
(widened palpebral fissure)

12.              
EYE SIGNS 

•
Naffziger’s sign
: For proptosis

•
Moebius sign
: Loss of convergence (Due to ophthalmoplegia)

•
Joffroy’s sign
: Absence of wrinkling of forehead on looking up.

13.      
THYROTOXICOSIS- SIGNS 
•
Dermopathy
: Pretibial myxedema due to increased
mucopolysaccharide deposition.

•
Thyroid acropachy
: Dermopathy associated with
clubbing of toes

•
Tremors
: Outstretched hands,tongue

•Grave’s disease is diagnosed when features of
thyrotoxicosis is associated with ophthalmopathy +/ -
dermopathy

14.    
GRAVE’S DISEASE-OPHTHALMOPATHY 

15.            
DIAGNOSIS 
•Most cases can be diagnosed clinically.

•Thyroid function test : Raised T3,T4 with decreased TSH.

•Thyroid scan : I123 scan-Diffuse increased uptake.

•FNAC : Relative contraindication in the presence o f
thyrotoxicosis.

16. HISTOPATHOLOGY OF GRAVE’S DISEASE-  FOLLICULAR HYPERTROPHY WITH SCANTY COLLOID 

19.      
TREATMENT OPTIONS 
•
Medical
•
Radio-Iodine
•
Surgery

20.   MEDICAL TREATMENT –DRUGS USED 
•
Anti thyroid drugs
: Carbimazole and propylthiouracil
•
Mechanism of action
: Inhibit thyroid peroxidase and thereby interfere with
iodination of tyrosine residues in thyroglobulin an d coupling of iodotyrosine
residues to form T3 and T4.
•
Dose
: Start with high dose (Carbimazole 10mg TDS ) once control is
achieved dose is reduced (5 mg BD or TDS)
•
Alternatively block and replacement regimen
is used – Continue with high
dose of antithyroid drugs with thyroxine supplement ation (0.1 mg OD) .
Decreased risk of iatrogenic hypothyroidism .
•
Adverse effects
: Agranulocytosis less common but serious adverse effect.
Needs monitoring of counts.

21.        
MEDICAL TREATMENT-  
ADVANTAGES: 
  •Can be used even in children and young adults.

•Hypothyroidism if induced is reversible

•No complications associated with surgery.

Disadvantages:

•Prolonged treatment is required since relapse rate is high.

•Drug toxicity

22.        
BETA BLOCKERS 

•Propranolol most commonly used

Indications
:
• For symptomatic control
•When antithyroid drugs are initiated till biochemic al
control is achieved
•Thyroid storm
•Along with iodide for preop preparation.

•Dose : 20-40 mg QID (Max dose – 600mg/day)

23.            
IODIDES 
•Lugol’s iodine most commonly used preparation (5% i odine in 10%
potassium iodide solution).

Mechanism of action : •Inhibition of thyroid hormone release (Thyroid cons tipation)
•Decreases vascularity of the gland

Uses: •Preop preparation : 10-14 days prior to surgery
•Thyroid storm :iodinated contrast agents (sodium ip odate ) given i.v.

Dose
: Lugol’s iodine 5 drops TDS in milk.

24.      
RADIOACTIVE IODINE ABLATION 
•I131 most commonly used

Indications :

•Patients with small to moderate enlargement of glan d
and antithyroid drugs have clearly not worked.

•Patients not willing for surgery or for whom surger y is
contraindicated.

•Recurrence after surgical or medical therapy.

25.  
RADIOACTIVE IODINE ABLATION 
Euthyroid state achieved by using antithyroid drugs for
3-4weeks before treatment.
↓
Interruption of antithyroid drugs for 3-4 days befo re and after Iodine
treatment to permit adequate accumulation and reten tion of
administered iodine.
↓
Pretreatment radioiodine scan done (25-100 micro cu rie of I131 given) to
calculate therapeutic dose.
↓
Therapeutic dose of radio-iodine given (usually 8-1 2 milli curie) orally.

26.    
RADIOACTIVE IODINE ABLATION 
•Patient rendered euthyroid by 8-12 weeks after trea tment. Disadvantages : •Hypothyroidism : incidence 10-15% by 1 year which
increases by 3% in each succeeding year.
•Exacerbation of cardiac arrhythmias in elderly
•Fetal damage-hence contraindicated in pregnant and
lactating women
•Worsening of ophthalmopathy – avoided by using
prophylactic steroids
•Can induce Thyroid storm if patients are not render ed
euthyroid before radio-iodine administration.

27.     RADIOACTIVE IODINE ABLATION  •Carcinogenic effect of radio-iodine has been
ruled out and hence radio-iodine can be safely
used in all individuals over 25 years i.e when
development is complete.

28.          
SURGERY 
Indications : •Failure of medical/radioiodine treatment

•Younger patients particularly adolescents

•Pregnant patients

•Patients with suspicious masses contained within th e large
thyroid.

•Patients with severe cosmetic deformities or trache al
compression causing discomfort.

29.            
SURGERY 
•Extent of surgery : Subtotal or total thyroidectomy

Advantage of total thyroidectomy : •Recurrence is avoided
•Patients with ophthalmopathy are stabilized most
successfully by total thyroidectomy.(Due to removal of
entire antigenic focus)

•Patients should be rendered euthyroid before surger y
to avoid thyroid storm.

30.    
THYROID STORM-TREATMENT 
•
Supportive measures :
Correction of dehydration with I.v
fluids and hyperpyrexia with cooling blankets
•
Antithyroid drugs :
Propylthiouracil preferred.Given through
Ryle’s tube if patient can’t take orally.(Parentera l forms not
available).
•
Iodinated contrast agents
(sodium ipodate)-1gm given I.v
•
Propranolol
2mg I.v with ECG monitoring (if patient cannot
take orally) or 40-80mg Q6h
•
Large doses of dexamethasone
: 2mg Q6h (inhibit hormone
release,peripheral conversion of T4toT3 and provide adrenal
support.
•
Life threatening circumstances
: Peritoneal or hemodialysis to
lower T3 andT4 levels.

31.    
OPHTHALMOPATHY-TREATMENT 
•
Mild disease
– Conservative measures: Elevating the head at
night ,Protection of eye ball and avoiding corneal drying by
applying 1%methylcellulose eye drops or plastic shi elds.

•Severe cases
–large doses of prednisolone (100-120
mg/day)

•
Malignant exopthalmos
: Orbital decompression.

32.     THYROTOXICOSIS IN              
    PREGNANCY 
•Radio-Iodine : Contraindicated.
•Surgery : Can be done in second trimester
•Chance of miscarriage present with surgery.
•Antithyroid drugs : Propylthiouracil preferred
(Placental transfer less)
•Can cause fetal goitre.
•Avoided by keeping antithyroid drug dosage to
minimum to prevent rise in TSH.

33.  
TOXIC MULTINODULAR GOITER-          
    PLUMMER’S DISEASE                
       
•Seen in long standing goitre when one or more nodul es
become autonomous.
•Cardiovascular symptoms predominate
•Radionuclide scan: Can demonstrate autonomous nodul es.
•Treatment :
• Antithyroid drugs : Can control symptoms but relap se
invariably occurs with discontinuation of medicatio ns.
•Propranolol can be used for symptomatic control.
•Radio-iodine : Effective.But larger doses are requi red 20-30
milli curie)

34. TOXIC MULTINODULAR GOITER-PLUMMER’S      
                  DISEASE 
•Chance of hypothyroidism with
radio-iodine is less compared to
grave’s disease due to variable
activity of different portion of the
gland allowing previously
quiescent area to function in
place of those destroyed by I 131.

•Surgery : Preferred treatment
(Subtotal thyroidectomy)

35.  
  TOXIC ADENOMA- GOETSCH’S       
 
              DISEASE  

36. THYROID SURGERY 

37. ROUTINE INVESTIGATIONS BEFORE 
THYROID SURGERY 
•X-ray soft tissue neck – AP and lateral view

•Indirect laryngoscopy

•Serum calcium : Baseline value to detect post-op hy pocalcemia
due to hypoparathyroidism (Optional)

38. TYPES 
•Hemithyroidectomy

•Subtotal thyroidectomy

•Near total/total thyroidectomy

39. TECHNIQUE 
•Anaesthesia : GA with ET tube

•Position : Supine with table tilted up by 15 degree to reduce venous
engorgement
•Neck extended by placing sandbags under shoulder.

•Incision : Skin crease incision about 2 finger brea dths above
suprasternal notch.

40. TECHNIQUE  •Flaps of skin,subcutaneous tissue and platysma rais ed upwards
to superior thyroid notch and downwards to the supr asternal
notch.
•Deep cervical fascia is divided in the midline bet ween the
sternothyroid muscles down to the plane of thyroid capsule.

41. THE THYROID LOBE IS EXPOSED BY MOBILIZING THE 
STRAP MUSCLES AWAY FROM THE LOBE BY MEANS OF 
LATERAL RETRACTION ON THE MUSCLES  
THE MIDDLE THYROID VEIN IS EXPOSED, DIVIDED, AND 
LIGATED.  

42. BABCOCK CLAMPS ARE APPLIED TO INFERIOR AND 
SUPERIOR (NOT SHOWN) ASPECTS OF THE THYROID 
LOBE TO FACILITATE MEDIAL RETRACTION ON THE 
GLAND.  

43.   
 
TECHNIQUE   
 
 
 

44. DOWNWARD TRACTION ON THE SUPERIOR BABCOCK CLAMP EXPOSES 
THE SUPERIOR POLE VESSELS, INCLUDING THE BRANCHES OF THE 
SUPERIOR THYROID ARTERY.  
THE EXTERNAL LARYNGEAL NERVE COURSES ALONG THE CRICOTHYROID 
MUSCLE JUST MEDIAL TO THE SUPERIOR POLE VESSELS. 
 TO AVOID INJURY TO THIS NERVE,  THE SUPERIOR POLE VESSELS ARE 
DIVIDED INDIVIDUALLY AS CLOSE AS POSSIBLE TO THE POINT WHERE 
THEY ENTER THE THYROID GLAND.  

45. AS THE THYROID IS RETRACTED MEDIALLY, GENTLE 
DISSECTION  IS USED TO EXPOSE THE PARATHYROID 
GLANDS, INFERIOR THYROID ARTERY, AND RECURRENT 
LARYNGEAL NERVE.  

46. TO PERFORM TOTAL LOBECTOMY, THE BRANCHES OF THE INFERIOR THYROID 
ARTERY ARE DIVIDED AT THE SURFACE OF THE THYROID GLAND. THE INFERIOR 
THYROID VEINS CAN NOW BE LIGATED AND DIVIDED. SUPERIORLY, THE CONNECTIVE 
TISSUE (LIGAMENT OF BERRY), WHICH BINDS THE THYROID TO THE TRACHEAL 
RINGS, IS CAREFULLY DIVIDED. THERE ARE USUALLY SEVERAL SMALL 
ACCOMPANYING VESSELS, AND THE RECURRENT NERVE IS CLOSEST TO THE 
THYROID AND MOST VULNERABLE AT THIS POINT.  

47. THE DISSECTION OF THE THYROID FROM THE TRACHEA CAN BE 
PERFORMED WITH THE CAUTERY BY DIVISION OF THE LOOSE 
CONNECTIVE TISSUE BETWEEN THESE STRUCTURES. DISSECTION IS 
EXTENDED UNDER THE ISTHMUS, AND THE SPECIMEN IS DIVIDED SO 
THAT THE ISTHMUS IS INCLUDED WITH THE RESECTED LOBE.  

48. SUBTOTAL LOBECTOMY NECESSITATES IDENTIFICATION OF THE PARATHYROID 
GLANDS, INFERIOR THYROID ARTERY, AND RECURRENT LARYNGEAL NERVE, AS 
PREVIOUSLY DESCRIBED. THE LINE OF RESECTION IS SELECTED TO PRESERVE THE 
PARATHYROID GLANDS AND THEIR BLOOD SUPPLY AND TO PROTECT THE 
RECURRENT LARYNGEAL NERVE. IT SHOULD BE BASED ON THE INFERIOR THYROID 
ARTERY OR ITS MAJOR BRANCHES.  

49. CLAMPS ARE PLACED ALONG THE LINE OF RESECTION AND THE 
THYROID GLAND IS DIVIDED. THE DIVIDED TISSUE IS LIGATED OR 
SUTURE-LIGATED WITH 3-0 SILK SUTURES.  

50. DURING THYROIDECTOMY, THE RECURRENT LARYNGEAL NERVE IS AT 
GREATEST RISK FOR INJURY (1) AT THE LIGAMENT OF BERRY, (2) 
DURING LIGATION OF BRANCHES OF THE INFERIOR THYROID ARTERY, 
AND (3) AT THE THORACIC INLET.  

52.    
POST-OP COMPLICATIONS 
•
Hemorrhage
: Tension hematoma deep to cervical fascia usually
result from slipping of ligature on the superior th yroid
artery.Requires emergency re-exploration.
•
Respiratory Obstruction
: Due to tension hematoma or
Tracheomalacia.
•Thyroid insufficiency-
hypothyroidism
•
Recurrent laryngeal nerve paralysis
•
Superior laryngeal nerve paralysis
•
Parathyroid insufficiency-
hypocalcemia
•
Wound infection
•
Hypertrophic scar