Thread: Thyroid Swelling- viva questions

Case 1. SIMPLE NODULAR GOITRE


Q. What is your diagnosis ?
A. Simple nodular goitre.


Q. Why this is a goitre ?
A. Because there is a swelling in the lower part of
the front of the neck which is the anatomical site
of the thyroid gland, having the shape of the
thyroid gland (butterfly) and this swelling moves
up and down with deglutition.


Q Why does a goitre move up and down with
deglutition ?
A. Because the thyroid gland is enclosed within
the pretracheal fascia which is attached to the
thyroid cartilage and hyoid bones.


Q. Mention other swellings that move up and
down with deglutition.
A. Subhyoid bursitis, prelaryngeal L.Ns.,
thyroglossal cyst, ectopic thyroid gland,
pretracheal L.N., cold abscess of the larynx,
parathyroid gland tumours, laryngocoele and
tracheocoele.


Q. When doesn't the goitre move up and
down with deglutition ?
A. In 1) Huge goitre, 2) Malignant goitre and 3)
Retrosternal goitre.

Q Why this is a simple goitre ?
A. Because there are no manifestations suggestive
of thyrotoxicosis, no manifestations suggestive of
malignancy and no manifestations suggestive of
inflammation.


Q. What are the manifestations suspicious of
malignancy in a goitre ?
A.
• From history : Short duration or long
duration with recent rapid enlargement in
size, pain referred to the ear, hoarseness of
voice, symptoms of distant metastases.
• From examination : Hardness, fixity to the
trachea, fixity to sternomastoid, attachment
to the skin overlying, absent carotid pulse
(Berry's ), enlarged deep cervical lymph
nodes, signs of distant metastases.



Q. How would you elicit fixity to the trachea ?
A. By fixing the trachea by one hand and trying to
move the gland up and down with the other hand,
normally there is a slight range of movement.


Q. How do you elicit fixity to the
sternomastoid ?
A. By asking the patient to swallow while pinching
the relaxed sternomastoid, normally I do not feel
something pulling on the sternomastoid between
my fingers.


Q. Can the cervical L.Ns. develop secondaries
from a thyroid carcinoma while the 1ry is not
felt clinically ?
A. Yes, in occult papillary carcinoma of the thyroid
gland. This was thought in the past as some form
of ectopic thyroid gland and was called "lateral
aberrant thyroid".

Q. What are the manifestations suspicious of
an inflammatory goitre ?
A.
• In acute and subacute thyroiditis : Short
duration, pain, may be fever (with or without
chills), warmth and tenderness over the
gland.
• In Hashimoto thyroiditis : Locally the gland is
very similar to S.N.G. but the course of the
disease is characteristic; early there is
thyrotoxicosis which is followed by
hypothyroidism.
• In Riedle's thyroiditis : The gland is
irregularly enlarged, hard, fixed to skin,
trachea, and sternomastoid i.e. very similar
to anaplastic carcinoma of the thyroid gland.


Q. What is the aetiology of simple goitre ?
A. Simple goitre is due to stimulation of the
thyroid gland by increased level of circulating
T.S.H. secondary to low levels of circulating
thyroid hormones secondary to either iodine
deficiency or defective synthesis of thyroid
hormones.

Q. What are the causes of iodine deficiency ?
A.
• 1) Decreased intake as in endemic areas,
• 2) Increased demands as in periods of stress
in the females (puberty, pregnancy,
lactation),
• 3) Decreased absorption from the G.I.T.


Q. What are the causes of defective synthesis
of thyroid hormones ?
A. 1) Enzymatic deficiency, and 2) Goitrogens
(Cabbage, P.A.S., antithyroid drugs and iodides in
large amounts "iodide goitre")


Q. What is Pendred's syndrome ?
A. This is a cretinoid goitre associated with
deafness.


Q. What is the cause of this goitre ?
A. Congenital deficiency of peroxidase enzyme.


Q. What are the types of simple goitre ?
A. 1. Simple diffuse goitre (Physiological goitre)
2. Simple nodular goitre (S.N.G.).


Q. Which of them is reversible ?
A. Physiological goitre can be reversible if the
cause of iodine defeciency is eliminated.

Q. What are the complications of simple
nodular goitre ?
A. 1) Pressure on surrounding structures
(dyspnoea and dysphagia), 2) Disfigurement, 3)
2ry toxic goitre (30%), 4) Haemorrhage in a cyst,
and 5) Malignant transformation (1/2%),
{Follicular Type}.


Q. How does a patient with a haemorrhage in
a cyst present ?
A. Sudden onset of dyspnoea.


Q. What is the cause of dyspnoea in such
cases ?
A. Sudden enlargement of the gland and more
important is the reflex spasm of the pretracheal
muscles.


Q. How do you manage such a patient ?
A. Emergency needle aspiration.


Q. What investigations do you want to do for
this patient with a goitre ?
A. In addition to the routine laboratory
investigations, we do thyroid function tests.

Q. What are the complications of subtotal
thyroidectomy for S.N.G.?
A. Complication of subtotal thyroidectomy for
S.N.G. include :
• 1. Tension haematoma (due to slipped
ligature from the superior thyroid artery),
• 2. Dyspnoea
• 3. Injury to the related nerves : 1) recurrent
laryngeal nerve, and 2) external laryngeal
nerve
• 4. Hypoparathyroidism (due to accidental
removal of the parathyroid glands),
• 4. Hypothyroidism (if the gland was removed
near totally and no postoperative
replacement by thyroxin was given),
• 5. Recurrent goitre (if no postoperative
thyroxin was given),


Q. What is the danger of haematoma after
thyroidectomy ?
A. It can lead to suffocation as it is enclosed
within the pretracheal muscles.


Q. How do you treat it ?
A. First, urgently, while the patient is in bed, the
sutures are cut to relieve the tension and the
patient is taken to the theatre to deal with the
bleeder.


Q. What are the causes of dyspnoea after
thyroidectomy ?
A. 1) Tension haematoma, 2) Laryngeal oedema
due to rough manipulations during the operation,
3) Bilateral recurrent laryngeal nerve injury, and 4)
Tracheomalacia (very rare).


Q. What are the effects of RLN injury ?
A.
&Unilateral RLN injury -------------> hoarseness of
voice which is improved by time due to
compensatory crossing of the contralateral cord to
the other side.
&Bilateral RLN injury -------------> Suffocation
which should be treated at once by emergency
tracheostomy.
Q. What is the effect of external laryngeal
nerve injury ?
A. Loss of high pitched voice due to paralysis of
cricothyroid muscle..

I enjoyed very much reading your writing on the thyroid topic and many thanks. I would suggest you enlarge on the recurrent laryngeal nerve injury as unilateral or bilateral complete or partial.