Thyroid And Parathyroid Gland Important Question And Answers

Thyroid And Parathyroid Gland

Question.1. Write short note on thyroid crisis.
Or
Write short note on thyroid storm/crisis.

Answer. It is also known as thyroid crisis or thyroid storm.

• It occurs in a thyrotoxic patient inadequately prepared for thyroidectomy.
• Other causes are infection, trauma, pre-eclampsia,diabetic ketosis, emergency surgery and stress.
• It is an acute life-threatening metabolic state which is induced by excess release of thyroid hormones in individuals with thyrotoxicosis.

Thyroid crisis Etiology

• Previously thyroid storm was a common complication of toxic goitre surgery during intraoperative and postoperative stages.
• In modern era thyroid storm is seen in a thyrotoxic patient with intercurrent illness or surgical emergency.
• Most common cause of thyroid storm is intercurrent illness or infection.
• Various other causes which rapidly increase the thyroid hormone levels are radioiodine therapy, withdrawal of antithyroid drug therapy, vigorous thyroid palpation,iodinated contrast dye, ingestion of thyroid hormone and sepsis or infection.

Read And Learn More: General Surgery Question And Answers

Thyroid crisis Clinical Features

• Thyroid crisis is present in l2–24 hours after surgery; with severe dehydration, circulatory collapse, hypotension, hyperpyrexia, tachypnea, hyperventilation, palpitation,restlessness, tremor, delirium, diarrhea, vomiting and cardiac failure; later coma.
• Bayley’s symptom complex of thyroid storm are insomnia,anorexia, diarrhea, vomiting, sweating, emotional instability, fever, tachycardia, aggravated toxic features,multiorgan dysfunction.

Thyroid crisis Treatment

• Patient should be sedated immediately with morphine or pethidine.
  Hyper pyrexia should be controlled by ice bag, rapid sponging, hypothermic blanket, and rectal ice irrigation.
• Oxygen is administered and IV glucose saline solution should be combat dehydration.
• Potassium may be added to control tachycardia.
  Hydrocortisone is often highly effctive.
• Lugol’s iodine should be given IV
  Propranolol should be used 20–40 mg 6 hourly.
• For atrial firillation, digitalis may be cautiously administered.
• Large dose of Propyl thiouracil orally, rectally or through Ryle’s tube.
  Saturated solution of potassium iodide.

Question.2. Write short note on solitary thyroid nodule.

Answer.

• It is the end stage result of diffuse goiter.
• Almost all the thyroid swellings initially present as solitary nodule.
• Solitary thyroid nodule is a discrete lesion/nodule within the thyroid gland and or radiologically distinct from surrounding thyroid parenchyma.

Solitary thyroid nodule Types

• Toxic solitary nodule—3—5% of solitary nodules of thyroid Nontoxic solitary nodule.

Based on radioisotope Study

• Hot: Means autonomous toxic nodule. Normal surrounding thyroid tissue is inactive and so will not take up isotope.
• Nodule is overactive. It is 5% common of which only 5%can be malignant.
• Warm: Normally functioning nodule. Nodule and surrounding normal thyroid will take up the isotope (active).
• It is l0% common of which l0% can be malignant.
• Cold: Nonfunctioning nodule; may be malignant (need not be always).
• Nodule will not take up isotope (underactive).
• It is 80% common of which 20% are malignant.

Solitary thyroid nodule Etiopathogenesis

• Puberty or pregnancy nodule
• Iodine deficiency nodule
• Adenoma
• Carcinoma
• Cyst.

Solitary thyroid nodule Clinical Features

• Common in female, seen in age group 20-40 year.
• Long duration of swelling in front of neck, dyspnea,dysphagia.
• Various obstructive signs are present i.e. stridor, tracheal deviation,
• neck vein engorgement.
• Single nodule is present.
• Hard area may suggest calcification and soft area necrosis.
• Sudden increase in size may occur due to hemorrhage.
• Solitary nodule has more tendencies to change in malignancy then
• MNG (multi-nodular goiter).

Solitary thyroid nodule Complication

• Calcification in long-standing.
• It may change into MNG (multi-nodular goitre).
• Sudden hemorrhage causes sudden enlargement of gland and even
• causes dyspnea.
• Patient may develop secondary thyrotoxicosis.

Solitary thyroid nodule Investigations

• Thyroid scan: This is basically a radioactive scan which makes out a hot or cold nodule.
  Hot nodules are not malignant and are toxic while cold nodules are malignant but they can be a simple cyst.
• Thyroid function tests: T3, T4 and TSH are not of use as most of the nodules are euthyroid.
• Ultrasound: It shows either cystic or solid nodule. Solid swellings can be edema or carcinoma.
• FNAC: It shows benign or indeterminate or malignant and at times it is undiagnostic also.
• Power Doppler can be done to know vascularity of the gland. Vascularity is described in resistive index.
• Serum calcitonin estimation is done if FNAC confims medullary carcinoma.
• CT scan or MRI can only be done in selective cases.
• X-ray of neck is done to see tracheal deviation.

Solitary thyroid nodule Management

• Non toxic benign nodule is treated with observation without any therapy.
  There is no role of any hormone therapy (L thyroxine).
  Annual clinical examination and ultrasound neck is needed during essential follow-up—any nodule of 20% increase in size or more than 2 mm increase in diameter warrants a repeat FNAC and hemithyroidectomy may be considered.
  Compressive symptoms and cosmesis are the indications for surgery,i.e. hemithyroidectomy.
• Solitary toxic nodule needs initial antithyroid drugs and then radioactive iodine therapy (5 m curie); occasionally surgery is done, i.e. hemithyroidectomy.
• During thyroid surgery complete thyroid gland should be explored properly.
  Care to be taken not to miss any similar nodule in any other part of gland.
  If there are no nodules and only solitary nodule is found it is resected with normal surrounding thyroid tissue, i.e. resection enucleation.
• If nodule is situated at junction of isthmus and the lobe, hemithyroidectomy is done.
  Histopathology of excised nodule is done. In histopathology report if there is presence of any evidence of malignancy immediate total thyroidectomy is done.

 

Question.3. Discuss differences in physiological, colloidal, and nodular goiter.

Answer.

Physiological Goiter

• It is called sporadic goiter
• Goiter is soft and diffuse
• Puberty, pregnancy goiter.

Colloidal Goiter

• It is the late stage of diffuse hyperplasia.
  TSH level have gone down and many follicles are inactive and full of colloid
• May be due to iodine deficiency.

Nodular Goiter

• The formation of nodules takes place due to fluctuating
  TSH stimulation and its level in circulation
• The nodule may be solid or cellular
• It may occur due to adenoma or carcinoma.

 

Question.4. Write short note on tetany

Answer. Tetany is a condition where is hyperexcitability of peripheral nerves.

Tetany Etiology

• It occur due the decrease in calcium level in blood.
• After thyroidectomy, there is decreased level of parathormone in the blood which leads to hypocalcemia. It is temporary and lasts for 4 to 6 weeks.
• Other causes are neck dissection, hemochromatosis, Wil-son’s disease, and DiGeorge syndrome.
• Severe vomiting, and hyperventilation associated with respiratory alkalosis.
• Metabolic alkalosis.
• Rickets, osteomalacia.
• Chronic renal failure.
• Acute pancreatitis

Tetany Clinical Features

• The fist symptoms of tetany are tingling and numbness in the face, fingers, and toes.
• Cramps are present in hand and feet.
• Stridor is the dangerous complication of severe tetany due to spasm of muscles of respiration.
• Spasm of intra-ocular muscles lead to blurring of vision.

Carpopedal spasm or Trousseau’s sign:

• It occurs in extreme cases and latent tetany.
• Armisflxedatelbow, wrist, and metacarpophalangeal joints but the inter-phalangeal joints are extended.
• Thumb means towards the palm.

Chvostek’s sign:

• It also occurs in latent tetany.
• It indicates facial hyperexcitability.
• If a tap is given to facial nerve infront of ear, *twitching of eyelids,
• corners of mouth takes place.

Laryngeal spasm:

• Increased excitability of the laryngeal muscles produces laryngeal
• spasm.
• This leads to blockage of respiratory passage and death may occur.
• Convulsions can occur in infants.

Tetany Diagnosis

• It is confimed by estimating serum calcium level which is less than 7 mg%.

Tetany Management

• Serum calcium estimation is done. It will be less than 7mg%.
• IV calcium gluconate 10% 10 mL 6 to 8 hourly is given.
• Later oral calcium (1 g TDS) with vitamin D supplementation (1–3 µg daily).
• Follow-up at regular intervals by doing serum calcium level
• Magnesium sulphate supportive therapy is also often needed—l0 mL 10% magnesium sulphate intravenously.

 

Question.5. Describe briefl parathyroid tumor.

Answer. Parathyroid adenoma and carcinoma are the neoplasm found in the parathyroid gland.

Parathyroid adenoma

• The most common tumor of the parathyroid gland is an adenoma.
• It may occur at any age and in either sex but is found more frequently in adult life.
• Most adenomas are fist brought to attntion because of excessive secretion of parathyroid hormones causing features of hyperthyroidism.
• Parathyroid adenoma is small, encapsulated, yellowish brown, ovoid nodular and weighing up to 5 g or more.

Parathyroid Carcinoma

• Carcinoma of parathyroid is rare and produces manifestation of hyperthyroidism
• Carcinoma tends to be irregular in shape and is adherent to the adjacent tissue.

Parathyroid tumor Treatment

• Single adenoma: Excision of the gland.
• Diffse hyperplasia: 3½ or 3¾ parathyroid are removed.
• Carcinoma: All four glands should be removed with thyroid tissue.

 

Question.6. Describe clinical symptoms, signs and treatment of primary thyrotoxicosis.

Answer.

Primary thyrotoxicosis Symptoms

• Hyperactivity, excitability irritability and dysphoria
• Heat intolerance and swelling
• Palpitations
• Hyperreflxia, muscle wasting proximal myopothy without fasciculations.
• Fatigue and weakness
• Weight loss with increased appetite
• Diarrhea and polyuria.
• Oligomenorrhea and loss of libido.
• Profuse sweating.
• Goitre or enlarged thyroid gland.

Primary thyrotoxicosis Signs

• Tachycardia is main sign which is present due to activation of
• thyrocardiac component
• Systolic hypertension is present
• Palms are hot and moist.
• Presence of tremors, i.e. involuntary movement of body parts is present.
• Cardiac arrhythmias, i.e. atrial firillation and atrial tachycardia develops.
• Diaphoresis is present, i.e. excessive sweating is present.
• There is presence of powerful wide pulse pressure and good bounding
• pulse is present.
• Exaggerated deep tendon reflxes are seen.
• There is protrusion of eyes, i.e. exophthalmus with staring look.
• Pretibial myxedema: Thickening of skin due to mucin deposition over tibia.

Primary thyrotoxicosis Treatment

General:

• Allow the patient to take mental and physical rest.
• Maintain nutrition of patient by giving nutritious diet.
• If patient is anxious alprazolam 0.25 to 0.5 mg BD is given.
• Most of the patients of thyrotoxicosis are fearful because ofincreased
• sympathetic activity. In such type of patient, propranolol 40-80 mg BD is given.

Drug therapy:

• Carbimazole is commonly used drug. It is started with 30 mg/day, adjustment of doses is made when patient come under control and maintenance dose is given,i.e. 10 to 20 mg/day.
• Potassium per chlorate 800 mg/day in divided doses is given and the dose is reduced with improvement in patient’s condition.
• Iodides are given, i.e. sodium or potassium iodide 6 to 10 mg/day.

Surgery:

• The commonly performed surgery is subtotal thyroidectomy, prior surgery anti-thyroids are given to make patient euthyroid. Potassium iodide 50 to 100 mg/day is given for 10 to 14 days.
• Radioiodine treatment: I131 is used and average effective dose is 8 to 10 millicuries.

 

Question.7. Write short note on hypothyroidism.
Or
Write short answer on management of hypothyroidism.

Answer. Inadequate release of thyroid hormone and its defective synthesis give rise to clinical synthesis of hypothyroidism.

Hypothyroidism Etiology

• After doing thyroidectomy
• Agenesis or dysgenesis
• Enzyme deficiency
• Iodine deficiency
• Hashimoto’s thyroiditis
• Antithyroid drugs
• Radioiodine
• Drugs: Lithium, amiodarone

Forms of Hypothyroidism

• Cretinism
• Myxedema.

Hypothyroidism Cretinism

• Congenital absence of thyroid hormone leads to condition called as cretinism.
• A cretin has retarded physical and mental growth.
• Child is obese with pads of fat in supraclavicular region,coarse features, limbs which are stumpy, thick lips and tongue, protuberant abdomen, small eyes, coarse hairs and dry skin.
• TSH will be raised; T3 and T4 will be low.
• Cretinism will be treated by L thyroxine once in a day in morning orally.

Hypothyroidism Myxedema

Myxedema is a clinical condition resulting from decreased circulating levels of T3 and T4.
It is characterized by deposition of mucinous material causing swelling of skin and subcutaneous tissue.

Hypothyroidism Clinical Features

• General: There is tiredness, somnolence (Prolongdrowsiness or sleepiness), weight gain, cold intolerance and goiter.
• Skin and sub-cutaneous tissue: Coarse dry skin, puffiss of face with malar flsh, baggy eyelids with swollen edematous appearance of supraclavicular regions, neck and lacks of hand and feet.
• Cardiovascular and respiratory features: Bradycardia, angina, cardiac failure, pericardial effsion and pleural effsion.
• Neuromuscular features: Aches and pains, cerebellar syndrome with slurred speech and ataxia, muscle cramps and stiffess.
• Gastrointestinal features: Constipation and ascites
• Developmental: Growth and mental retardation
• Reproductive system: Infertility, menorrhagia, hyperprolactinemia and galactorrhea.

Hypothyroidism Management

• In patient ofmyxedema adequate ventilation is maintained along with electrolyte balance and slow warming.
• Principle of therapy is replacement of defiient thyroid hormones.
• Replacement with L thyroxine 100 to 150µg/day. In old patients with ischemic heart disease initial therapy is with 25 to 50 µg/day and then gradually increased till the required dose. Drug may take at least a week to act.
• It is better to give the drug in morning hours to obviate sleeplessness.
  Initial rapid response is achieved by giving L iodothyronine 20µg TID.

 

Question.8. Etiology, clinical picture, and treatment of Grave’s disease.

Answer.

Grave’s disease Etiology
Grave’s disease is an autoimmune disease caused by production of autoantibodies that stimulate thyroid stimulating hormone receptor.

Grave’s disease Clinical Features

• There is presence of diffused goiter which is with or without bruit.
• Fever, anxiety and restlessness are present.
• There is weight loss, fatigue, sweating and heat intolerance.
• Cardiovascular features:
  • Tachycardia is present which persists during sleep.
  • Large pulse pressure is present with raised systolic blood pressure.
  • Cardiac arrhythmias are present.
  • Capillary pulsations may be seen.
• Ocular manifestations:
  • Primary manifestations: Proptosis, exophthalmos and ophthalmoplegia.
  • Secondary manifestations: Optic nerve compression,impaired convergence and exposure keratitis.
• Gastrointestinal: Weight loss, diarrhea and vomiting.
• Reproductive system: Oligomenorrhea and infertility.

Grave’s disease Management

• General
  • Allow the patient to take mental and physical rest.
  • Maintain nutrition of patient by giving nutritious diet.
  • Ifpatientisanxiousalprazolam0.25to0.5mgBDisgiven.
  • Most of the patients of thyrotoxicosis are fearful because ofincreased sympathetic activity. In such type of patient propranolol 40–80 mg BD is given.
• Drug therapy:
  • Carbimazole is commonly used drug. It is started with 30 mg/day, adjustment of doses is made when patient come under control and maintenance dose is given,i.e. 10–20 mg/day.
  • Potassium per chlorate 800 mg/day in divided doses is given and the dose is reduced with improvement in patient’s condition.
  • Iodides are given, i.e. sodium or potassium iodide 6 to 10 mg/day.
• Surgery: The commonly performed surgery is subtotal thyroidectomy, prior surgery anti-thyroids are given to make patient euthyroid. Potassium iodide 50–100 mg/day is given for 10–14 days.
• Radioiodine treatment
  I131 is used and average effctive dose is 8–10 millicuries.

 

Question.9. Write short note on hashimoto disease of thyroid.

Answer. It is an autoimmune disease
It is also called as Hashimoto’s thyroiditis or diffuse non-goitrous thyroiditis or struma lymphomatosis.

Hashimoto’s thyroiditis Clinical Features

• It is very common in women. Most common in perimenopausal females.
• There is painful, diffuse enlargement of both the lobes of thyroid gland which is fim, rubbery, tender and smooth.
• Initially, both lobes ofthyroid are present with toxic features butlater they manifest with the features of hypothyroidism.
• Hepatosplenomegaly can be present.
• The condition can predispose to papillary carcinoma of thyroid.

Hashimoto’s thyroiditis Histology

• Histology is characterized by extensive lymphocytic infitration resulting in destruction of thyroid follicles with
  variable degree of firosis.
• The thyroid follicles are destroyed by signifiant firosis.
• The deep eosinophilic staining thyroid follicular cell

Askanazy cell, is characteristic.

Hashimoto’s thyroiditis Investigations

• FNAC can be done
• Assessment of T3, T4 and TSH levels
• Thyroid antibodies assay: Signifiant rise is observed in 85% of cases.
• ESR is very high, i.e. over 90 mm/hour.

Hashimoto’s thyroiditis Treatment

• L-thyroxine 0.2 mg/day is given as a supplementary dose.
• lf there is compression on the trachea, isthmusectomy is done to relieve compression.
• lf the goitre is big and causing discomfort, subtotal thyroidectomy can also be done.
• Steroid therapy often is helpful.

Complications of Hashimoto’s thyroiditis

• Permanent hypothyroidism
• Papillary carcinoma of the thyroid
• Malignant lymphoma.

 

Question.10. Discuss briefl myxedema.

Answer. Myxedema is a clinical condition resulting from decreased circulating levels of T3 and T4. It is characterized by deposition of mucinous material causing swelling of skin and subcutaneous tissue.

Myxedema Clinical Features

• General: There is tiredness, somnolence, weight gain, cold intolerance and goiter.
• Skin and subcutaneous tissue: Coarse dry skin, puffiss of face with malar flsh, baggy eyelids with swollen edematous appearance of supraclavicular regions, neck and lacks of hand and feet.
• Cardiovascular and respiratory features: Bradycardia, angina,cardiac failure, pericardial effusion and pleural effsion.
• Neuromuscular features: Aches and pains, cerebellar syndrome with slurred speech and ataxia, muscle camps and stiffess.
• Gastrointestinal features: Constipation and ascites
• Developmental: Growth and mental retardation
• Reproductive system: Infertility, menorrhagia, hyperprolactinemia and galactorrhea.

Myxedema Investigation

• Thyroid function test: There is reduction in T3 and T4 levels and rise in serum thyroid stimulating hormone which indicates primary hypothyroidism.
  Reduction in T3 and T4 levels with TSH level below normal range is secondary hypothyroidism.
• Serum cholesterol: It is raised in primary thyroid failure.
• The fall in serum level is more than 50 mg/100 mL.
• Tendon reflx duration is prolonged.
• In ECG bradycardia, low voltage complexes and flttned or inverted T waves are present.

Myxedema Management

• In patient of myxedema adequate ventilation is maintained along with electrolyte balance and slow warming.
• Principle of therapy is replacement of deficient thyroid hormones.
• Replacement with L thyroxine 100 to 150µg/day. In old patients with ischemic heart disease initial therapy is with 25 to 50 µg/day and then gradually increased till the required dose.
  Drug may take at least a week to act.
  It is bettr to give the drug in morning hours to obviate sleeplessness.
• Initial rapid response is achieved by giving L iodothyronine 20µg TID.

 

Question.11. Write classification of thyroid swelling. Discuss treatment of simple goiter.

Answer. Classification of Thyroid Swelling

Thyroid Swelling Simple nontoxic

• Diffse hyperplastic:
• Physiological
  • Puberty
  • Pregnancy.
• Primary iodine deficiency
• Secondary iodine deficiency:
  • Goitrogens of Brassica family, e.g. cabbage,soyabean
  • Excess dietary floride.
  • Drugs: PAS, lithium, phenylbutazone, thiocyanates, potassium
  • perchlorate, anti-thyroid drugs, radioactive iodine.
  • Dyshormonogenetic goitre.
• Colloid goitre.
• Nodular goitre (Multinodular).
• Solitary nontoxic nodule.
• Recurrent nontoxic nodule.

Thyroid Swelling Toxic

• Diffse (Primary)—Grave’s Disease.
• Multinodular (Secondary)—Plummer’s disease.
• Toxic nodule (solitary) (Tertiary).
• Recurrent toxicosis.

Thyroid Swelling Neoplastic

• Benign Adenomas: follicular, Hurthle cell.
• Malignant:
  • Carcinomas: Papillary, follicular, medullary,anaplastic.
  • Lymphomas.

Thyroid Swelling Thyroiditis

• Hashimoto’s autoimmune thyroiditis.
• De-Quervain’s autoimmune thyroiditis.
• Riedel’s thyroiditis.

Rare causes: Bacterial (suppurative), amyloid.

Treatment Of Simple Goiter

• When entire gland is diseased total thyroidectomy is done.
• Subtotal thyroidectomy is done depending on the amount of gland involved, amount of normal gland existing and location of nodules.
  It is a commonly done procedure in multinodular goitre.
  Eight grams of thyroid tissue is retained in each lateral lobe.
• Often partial thyroidectomy or Hartley Dunhill operation (isthumus + one entire lateral lobe and opposite side subtotal or partial) is also done depending on the amount of diseased gland and normal tissues behind.
• Partial thyroidectomy is not well approved now.
• Postoperative L thyroxine is often given to prevent any flctuation in TSH level which may cause recurrent nodule formation.

Question.12. Write differential diagnoses between follicular carcinoma and medullary carcinoma of thyroid regarding etiopathology, clinical picture, metastasis and management.

Answer. See the table below

 

Question.13. Write short note on hyperthyroidism.

Answer. Hyperthyroidism is the condition resulting from the effect of excessive amounts of thyroid hormones on body. In hyperthyroidism, pathology is in thyroid gland itself.

Hyperthyroidism Etiology

• Exophthalmic goiter leads to hyperthyroidism. The condition is ch
• Pituitary diseases which occurs in or involves anterior lobe of pituitary gland.
• Toxic adenoma
• Multi-nodular goiter
• Ectopic thyroid tissue.

Hyperthyroidism Clinical Features

• It occurs at the age of 20 to 40 years.
• Female predilection is present.
• Thyroid become enlarged, nodular, smooth and asymmetrical.
• Gastrointestinal features: Weight loss and diarrhea
• Cardiovascular features: Palpitation, shortness of breadth at rest, angina, irregularity in heart rate.
• Neuromuscular features: Undue fatigue and muscle weakness, tremors
• Skeletal features: Increase in linear growth in children
• Genitourinary system: Oligomenorrhea or amenorrhea,occasional urinary frequency
• Integumentary system: Hair loss, gynecomastia, pruritus,palmer erythema.

Hyperthyroidism Treatment

Anti-Thyroid Drugs
Drugs such as carbimazole 5–10 mg 8 hourly is given for 12-16 months; Methimazole can also be given; Propyl thiouracil is given 200 mg 8 hourly.

Hyperthyroidism Surgery

• Before doing thyroid surgeries patient should become euthyroid.
• Subtotal thyroidectomy: Both lobes with isthmus are removed and a tissue equivalent to pulp of figer is retained at lower pole of gland bilaterally.

Hyperthyroidism Radioiodine Therapy

• It destroys the cells and causes the complete ablation of thyroid gland.
• It should be given after the age of 45 years.
• Dosage is 5–10 millicurie.

 

Question.14. Define and classify goiters. Describe differentiating features between primary and secondary thyrotoxicosis along with medical treatment to make patient euthyroid.

Answer. Diffuse enlargement of thyroid gland is described as goiter.

Classifiation of Goiter

Simple goitre:

• • Puberty goitre
  • Colloid goitre
  • Iodine-defiiency goitre
  • Multinodular goitre.

Toxic goitre:

• • Graves disease
  • Secondary thyrotoxicosis in multinodular goitre
  • Solitary nodule
  • Other causes.

Neoplastic goitre:

• • Benign adenoma (Follicular adenoma)
  • Malignant tumors; They are further classifid into

A.PRIMARY

• Well-diffrentiated carcinoma
  • Papillary carcinoma
  • Follicular carcinoma.
• Poorly diffrentiated carcinoma
  • Anaplastic carcinoma
• Arising from parafollicular cells
  • Medullary carcinoma.
• Arising from lymphatic tissue
  • Malignant lymphoma.

B.SECONDARY (Metastasis)

• Malignant melanoma, renal cell carcinoma, breast carcinoma produce
• secondaries in the thyroid, due to blood spread.

Thyroiditis

• • Granulomatous thyroiditis
  • Autoimmune thyroiditis
  • Riedel’s thyroiditis.

Other rare causes of goitre

• • Acute bacterial thyroiditis
  • Thyroid cyst
  • Thyroid abscess
  • Amyloid goitres.

Differentiating Features between Primary and Secondary thyrotoxicosis

Medical treatment to Make Patient euthyroid

• Carbimazole 10 mg 6 to 8 hourly intervals daily, till the patient is euthyroid, after 8 to 12 weeks dosage may be reduced to 5 mg 8 hourly.
  Last dose is given in the evening before surgery.
• Propyl thiouracil is given as 200 mg 8 hourly.
• Lugol’s iodine, i.e. 5% iodine in 10% potassium iodide solution: 10 drops TDS for 2 weeks before operation to reduce vascularity.
• Thyroxine 0.1 mg daily to prevent TSH stimulation which may increase size and vascularity of the gland.

 

Question.15. Enlist midline neck swellings. Describe surgical anatomy of thyroid gland with reference to embryology,blood supply relationship and nerves related to thyroid gland.

Answer.

Enlisting Of Midline Swellings Of Neck

The midline swellings of neck are:

• Ludwig’s angina
• Enlarged sub-mental lymph node
• Sub-lingual dermoid cyst
• Thyroglossal cyst
• Sub-hyoid bursitis
• Goiter of thyroid, isthmus and pyramidal lobe
• Enlarged lymph node and lipoma in substernal space of burns
• Retrosternal goiter
• Thymic swelling
• Bony swelling arising from the manubrium sterni.

Surgical anatomy of thyroid Gland

Reference To Embryology

• It develops from median down growth (midline diverticulum) of a column of cells from the pharyngeal flor between fist and second pharyngeal pouches.
• By 6 weeks of time the central column, which becomes thyroglossal duct, gets reabsorbed.
• The duct bifurcates to form thyroid lobes.
• Pyramidal lobe is formed by a portion of the duct.

Reference To Blood Supply

Artery Supply

• The superior thyroid artery is a branch of external carotid artery, enters the upper pole of the gland, divides into anterior and posterior branches and anastomoses with ascending branch of inferior thyroid artery.
  Upper pole is narrow, hence ligation is easy.
• Inferior thyroid artery is a branch of thyrocervical trunk and enters the posterior aspect of the gland.
  It supplies the gland by dividing into 4 to 5 branches which enter the gland at various levels (not truly lower pole).
• Thyroidea ima artery is a branch of either brachiocephalic trunk or direct branch of arch of aorta and enters the lower part of the isthmus in about 2 to 3% of the cases.

Venous Drainage

• Superior thyroid vein drains the upper pole and enters the internal jugular vein. The vein follows the artery.
• Middle thyroid vein is single, short and wide and drains into internal jugular vein.
• Inferior thyroid veins form a plexus which drain into in nominate vein. They do not accompany the artery.
• Kocher’s vein is rarely found (vein in between middle and inferior thyroid vein).

Reference To Nerve Supply

• External laryngeal nerve: Vagus gives rise to superior laryngeal nerve, which separates from vagus at skull base and divides into two branches.
  The large, internal laryngeal nerve is sensory to the larynx.
  The small external laryngeal nerve runs close to the superior thyroid vessels and supplies cricothyroid muscle (tensor of the vocal cord) and is sensory to upper half of the larynx.
  This nerve is away from the vessels near the upper pole.
  Hence, in thyroidectomy, the upper pedicle should be ligated as close to the thyroid as possible.
• Recurrent laryngeal nerve: It is a branch of vagus, hooks around ligamentum arteriosum on the left and subclavian artery on the right, runs in tracheo, esophageal groove near the posteromedial surface. Close to the gland, the nerve lies in between (anterior or posterior) the branches of inferior thyroid artery.
  Hence, inferior thyroid artery should be ligated away from the gland, to avoid damage to recurrent laryngeal nerve.
  On right side it is 1 cm within the tracheoesophageal groove.
  The nerve traverses through the gland in about 5–8% of cases.
  The nerve may be very closely adherent to the posteromedial aspect of the gland.
  Nerve not seen may be far away in the tracheoesophageal groove.
• Non-recurrent laryngeal nerve is found in about l in 1,000 cases.
  Nerve has a horizontal course. In 25% of the cases it is within the ligament of Berry.

 

Question.16. Write the differential diagnosis of malignant tumors of thyroid with special reference to their management.

Answer.

 

Question.17. Write on classification of thyroiditis with clinical picture, etiology, and management.

Answer. Classification

Revised American Thyroid Association Classification

• Acute thyroiditis
• Sub-acute thyroiditis (de Quervain’s)
• Chronic autoimmune thyroiditis Or Hashimoto’s disease
• Post partum and silent thyroiditis
• Riedel’s thyroiditis.

Classification of Thyroiditis in Relation to Inflammation response and Clinical Course

Etiology, Clinical Picture And Management Of Thyroiditis

 

Question.18. Describe the classification, clinical features, and management of thyroid neoplasia.
Or
Write about clinical features of papillary and follicular carcinoma of thyroid and management

Answer.

Classification of Thyroid Neoplasia

Benign

• Follicular adenoma—Colloid, embryonal, fetal
• Hurthle cell adenoma
• Colloid adenoma
• Papillary adenoma.

Malignant (Dunhill classifiation)

Diffrentiated:

• Papillary carcinoma
• Follicular carcinoma
• Papillo-follicular carcinoma behaves like papillary carcinoma of thyroid
• Hurthle cell carcinoma behaves like follicular
  carcinoma.

Undifferentiated:

• Anaplastic carcinoma

Medullary carcinoma

Malignant lymphoma

Secondaries in thyroid from colon, kidney, melanoma and breast.

Clinical Features and Management of thyroid neoplasias

Question.19. Etiopathology, clinical picture, and management of a case of secondary thyrotoxicosis. Write indication, contraindications and complications of methods applied for the treatment.

Answer. Secondary hyperthyroidism is the result of abnormal,excessive thyroid-stimulating hormone (TSH) release and stimulation of the thyroid resulting in excessive T4 release.

Etiopathology Of Secondary Thyrotoxicosis

• Autoimmune: Here the thyroid IgG antibodies stimulate thyroid to produce more hormone.
  This mechanism causes diffse enlargement of thyroid along with the hyperfunction.
  The antibodies which are directed specifially against TSH receptors are known as thyroid receptor antibodies.
  There is presence of circulating antibodies and lymphocytic infiltration of thyroid tissue.
• Genetics: Association of HLA B8 DR3 and DR4 indicates the genetic susceptibility to environmental factors such as viruses and bacteria which may produce antibodies which cross react with TSH receptors and causes thyrotoxicosis

Clinical Picture Of Secondary Thyrotoxicosis

• It occurs during 25 to 40 years of age.
• Swelling is present for the long time while symptoms remain for shorter duration.
• Skin over the swelling is not warm.
• Consistency of the swelling is fim to hard and surface is nodular.
• On auscultation bruit is commonly heard.
• Cardiovascular symptoms are predominant, i.e. Tachy-cardia—may be atrial fibrillation, presence of wide pulse pressure, extrasystole and/or heart failure.
• CNS and GIT manifestations are less predominant.
• Internodular tissues of gland are overactive.

Secondary Thyrotoxicosis Management

Secondary Thyrotoxicosis Antithyroid Drugs

Carbimazole and propylthiouracil should be given.
Treatment should be started 48 hours later and should be continued till radioiodine has had its effect till 6 weeks.
Carbimazole should be given in dose of 40 to 60 mg, treatment should be continued for 12 to 18 months.

Indication

• In all patients preoperatively.
• In patients not willing for surgery
• In recurrence after surgery.

Contraindication

• In cases with hypersensitivity
• Anemia or leukemia
• Kidney or liver disease.

Complications

• Agranulocytosis
• Arthralgia
• Skin rashes
• Fever.

Radioactive Iodine

I131 should be given 150 microcuries per gram orally.

Indication

• In patients over the age of 40 years.
• Toxicity recurring after previous subtotal thyroidectomy.
• In very nervous patients who have fear of surgery.
• In patients with severe thyrotoxic heart disease.

Contraindications

• In patients under 45 years of age because of high incidence of hypothyroidism.
• During pregnancy and lactation.

Complication

• Hypothyroidism
• Worsening ophthalmopathy
• Risk for cancer and birth defects in long standing cases.

Subtotal thyroidectomy

• If cardiac symptoms are controlled well and risk of anesthesia is acceptable, subtotal thyroidectomy is done.
• Before surgery, it should be remembered that patient should be euthyroid. Antithyroid drugs should be stopped
  two weeks before surgery and is replaced by potassium iodate 170 mg daily orally.
• In the surgery, both lobes with isthmus are removed and a tissue equivalent to the pulp of figer is retained at lower pole of gland on both sides.

Indications

• In recurrent thyrotoxicosis after 12 to 18-month course of
  antithyroid drugs under the age of 40 years.
• In cases with sensitivity reactions to antithyroid compounds.
• In severe thyrotoxicosis not responding to medical treatment.
• In tracheal compression.

Contraindications

In patients showing evidence of marked exophthalmos.

Complications

• Hemorrhage
• Hematoma formation
• Edema of glotts
• Injury to recurrent laryngeal nerve
• Tetany.

 

Question.20. Write short note on parathormone.

Answer. Parathormone is secreted by chief cells whenever serum calcium falls.

Parathormone stimulate osteoclast cells for bone resorption, kidney for promoting calcium reabsorption and production of 1, 25 dihydroxy vitamin D and gastrointestinal tract to promote absorption of calcium and phosphorus.

Half-life of parathormone is 4 minutes.

In nomal persons the parathormone is balanced by calcitonin.

Actions Of Parathormone

• It increases absorption of calcium from gut.
• It mobilizes calcium from the bone.
• It increases calcium reabsorption from renal tubules and promote excretion of phosphate.

 

Question.21. Classify thyroid swellings. Describe pathogenesis, clinical features, and management of multinodular goiter.

Answer.

Multinodular Goiter

Multinodular growth is a discordant growth with structurally and functionally altered thyroid follicles which present multiple nodules in thyroid.

Multinodular Goiter Pathogenesis

Following is the pathogenesis of multinodular goiter.

Multinodular Goiter Clinical Features

• Multinodular goiter is more common in females. Female to male ratio is 10:1
• It occurs during the age of 20 to 40 years.
• It is a slowly progressive disease.
• There is presence of multiple nodules of various sizes which are present in both lobes and in isthmus which are fim,nodular, non-tender and does not move with deglutition.
• Swelling remain in front of neck, dyspnea is present due to tracheomalacia.
• Dysphagia is also present.
• Hard areas suggest calcifiation and soft areas are suggestive of necrosis.

Multinodular Goiter Management

Management part consists of both investigations and treatment:

Multinodular Goiter Investigations

• T3, T4, TSH and ultrasound neck and FNAC. FNAC should be done from the most dominant and suspected nodule.
  Ultrasound-guided FNAC is more reliable.
  This method identifies impalpable nodules, their number, nature of nodule, and vascularity of nodule.
• X-ray neck: It shows rim of calcification which shows displacement and compression of trachea.
• Indirect laryngoscopy: It shows the mobility of vocal cords.
• Radioisotope iodine scan: It should be done in selected patients only.
• Complete blood picture, routine urine examination, fasting and post prandial blood sugar, serum calcium estimation should be done.

Multinodular Goiter Treatment

Treatment for multinodular goiter is surgical.

• When complete gland is affcted total thyroidectomy should be done.
• Subtotal thyroidectomy is carried out depending on amount of gland involved and amount of normal gland left along with location of nodules. In this 8 g of thyroid tissue is retained in each lateral lobe.
• Postoperatively L-thyroxine is given to prevent any flctuation in TSH which can lead to recurrent nodule formation.

Multinodular Goiter Prevention

• When patient develops goiter in puberty he/she should be supplemented with 0.1 to 0.2 mg of L thyroxine.
• Patient should be given iodine rich diet.
• Goitrogenic diet, i.e. cabbage and goitrogenic drugs should be avoided.

 

Question.22. Describe the classification, clinical features, treatment, and complications of thyroid malignancy.

Answer. Classification of thyroid malignancy Or Dunhill

Classification

• Differentiated (80%)
  Papillary carcinoma (60%)
  Follicular carcinoma (17%)
  Papillo-follicular carcinoma
  Hurthle cell carcinoma.
• Undifferentiated—20%
  Anaplastic carcinoma (13%).
• Medullary carcinoma (6%)
• Malignant lymphoma (4%)
• Secondaries in thyroid—from colon, kidney,melanoma, breast.

Clinical Features and treatment of thyroid Malignancy

Complications of thyroid Malignancy

Complications of thyroid malignancy are associated with the thyroidectomy procedure followed as surgical treatment in most of thyroid malignancies.
So following are the complications:

Hemorrhage

• Chances of reactionary hemorrhage are present which is more dangerous and occurs within 6 to 8 hours after surgery.
  It occurs due to slipping of ligature, coughing, etc.
• Tension hematoma develop deep-to-deep fascia it com presses the larynx.

Respiratory Obstruction

It occur due to hematoma or laryngeal edema, due to tracheomalacia or bilateral recurrent laryngeal nerve palsy.

Recurrent Laryngeal Nerve Palsy

It can be transient or permanent. Transient recover in 3 weeks to 3 months. It presents with hoarseness of voice, aphonia, aspiration and ineffctive cough.

Hypoparathyroidism

It is temporary and due to vascular spasm of parathyroid glands. It occurson 2nd and 5thpost-operative day. It presents with weakness,positive Chvostek’s sign, carpopedal spasm, and convulsion.

Thyrotoxic Crisis

It occurs in thyrotoxic patient which is inadequately prepared for thyroidectomy.

Injury to external laryngeal nerve

It leads to weakening of cricothyroid muscle which causes alteration in pitch of voice, voice fatigue, breathy voice, and frequent throat clearing.

Hypothyroidism

It reveals clinically after 6 months.

Stitch Granuloma

It can occur with or without sinus formation and is seen after the use of non-absorbable suture material.

 

Question.23. Describe differentiating features of primary and secondary thyrotoxicosis.

Answer. Following are the differences between primary and secondary thyrotoxicosis:

 

Question.24. Write short note on complications of thyroid surgery.

Answer. Complications of thyroid surgery can be divided into three parts i.e. minor, rare, or major.

Minor complications: Postoperative surgical site seromas,poor scar formation.

Rare complications: Damage to the sympathetic trunk.

Major complications:

• Bleeding: Present with neck swelling, neck pain, and/or signs and symptoms of airway obstruction (e.g. dyspnea, stridor, hypoxia).
• Injury to recurrent laryngeal nerve: Present with postoperative hoarseness or breathlessness.
• Hypoparathyroidism: Signs of hypocalcemia, i.e.circumoral paresthesias, mental status changes,tetany, carpopedal spasm, laryngospasm, seizures, QT prolongation on ECG, and cardiac arrest.
• Thyrotoxic storm
• Injury to superior laryngeal nerve: Mild hoarseness or decreased vocal stamina.
• Infection: Manifests as superficial cellulitis or as an abscess.