thyroid gland

Which level of LN are affected first in thyroid ca

Delphian LN - level 6

The first lymph node to enlarge which may indicate malignancy

Which nerves run in close proximity to the thyroid gland and what happens when injury occurs to these nerves

Superior laryngeal nerve - injury causes monotonic boice

Recurrent laryngeal nerve- (more dangerous)

Injury causes the following

Unilateral - hoarseness of voice

Bilateral - respiratory obstruction, dyspnea & stridor

Explain semon’s law

Progressive lesion of RLN

Abductors will be paralysed before adductors

Partial injury : vocal cord will be brought to the midline

Complete injury: paramedian position of the vocal cords ( cadaveric position)

Mnemonic : B before D

Partial - abductors lost

Complete- cadaveric pos

What is the difference between subtotal and near total thyroidectomy

Sub-total: part of the thyroid tissue is preserved from both lobes ( right&left)

Near total: part of the thyroid tissue is preserved from one side (right or left)

What are the post-operation complications of thyroidectomy

Mnemonic 6s ( early complications)

1- serious hemorrhage

2- surgical site infection

3-surrounding nerves damage

4-storm

5-serum calcium low (hypocalcemia)

6-suffocation (respiratory obstruction)

The most common cause of hypoparathyroidism is thyroid surgery which develops after 3-5 days what are the clinical features

1- perioral tingling and numbness

2- chvostek sign

3- trousseau sign

4- carpopedal spasm

What are the types of simple goiter

1- diffuse hyperplastic goiter (during stress periods like puberty or pregnancy)

2-colloid goiter (if the stress ressolves after long period)

3-nodular goiter (repeated stress with fluctuations in TSH. Stimulation)

What is the natural history of simple goiter

Persistent stimulation ——> diffuse hyperplastic goiter (homogenous enlargement) ———> fluctuation in TSH stimulation ———→ active & inactive lobules———→ hemorrhage, degeneration & necrosis of active lobules———> nodular goiter

What is the most common sign of retrosternal goiter

Pemberton’s sign ( asking the patient to raise their arms for 2-3 min will cause facial flushing and dyspnea. It is due to compression of SVC

What is diffuse toxic goiter

Second name is grave’s disease

The whole thyroid gland is enlarged and overactive by TSH- receptor Ab

Enlargement:- diffuse and usually symmetrical

Nodules :- not required

Eye signs:- may have Grave’s opthalmopayhy

Mechanism:- autoimmune stimulation

What is the choice of therapy of grave’s disease

1st line :- antithyroid drugs with radioiodine for relapse

If failed

Surgery

What is the choice of treatment for toxic nodular goiter

1st line :- surgery

Drugs and radioiodine is not effective

What is the pre-operative preparations for thyrotoxic patients before surgery

1-carbimazole for 8-12 weeks (anti-thyroid)

2- propranolol :- beta blocker abolishes clinical manifestations

3- iodine :- reduces vascularity given in combination with carbimazole and propranolol

What is the gold standard investigation to determine the physical characteristics of thyroid swellings

US

Features of malignancy

1-microclacification

2- increased vascularity

3- macroscopic capsular breach

4- nodal involvement

Types of thyroid cancer

1- papillary carcinoma 80%

2- follicular carcinoma 10%

3- anaplastic carcinoma 5%

4- medullary carcinoma 2.5%

5- lymphoma 2.5%

What are the microscopic features or pap. Carcinoma

1- orphan annie eye nuclei

2- papillary projections

3- intranuclear grooves

4- psammoma bodies

What are the microscopic features of follicular carcinome

hurthle cells with abundant granular eosinophilic cytoplam

How can we distinguish between follicular adenoma and carcinoma

The distinguishing is based on histological exam. In adenoma there is no envasion of the capsular or pericapsular blood vessels