Thyroid

Question 1

What is the most common cause of congenital hypothyroidism worldwide?

Answer 1

Iodine deficiency (endemic goiter)

Question 2

What is the most common cause of permanent congenital hypothyroidism in iodine-sufficient areas?

Answer 2

Thyroid gland dysgenesis (80-85% of cases)

Question 3

What is the typical clinical presentation of congenital hypothyroidism in infants?

Answer 3

Large posterior fontanel, macroglossia, prolonged jaundice, umbilical hernia, constipation, hypotonia, hypothermia, lethargy

Question 4

What is the first-line treatment for congenital hypothyroidism?

Answer 4

Levothyroxine (10-15 µg/kg/day)

Question 5

What is the goal of levothyroxine therapy in congenital hypothyroidism?

Answer 5

To maintain serum FT4 in the upper half of the normal range

Question 6

What is the incidence of congenital hypothyroidism?

Answer 6

1/4000 to 1/2000 worldwide

Question 7

What is the role of TRH in fetal development?

Answer 7

TRH can be detected by 10-14 weeks of gestation and is part of the hypothalamic-pituitary-thyroid axis

Question 8

What is the significance of a TSH level >40 mIU/L in a newborn?

Answer 8

It is concerning for congenital hypothyroidism

Question 9

What is the most common cause of hypothyroidism in children and adults?

Answer 9

Hashimoto thyroiditis (autoimmune thyroiditis)

Question 10

What is the female-to-male ratio in Hashimoto thyroiditis?

Answer 10

0.16736111111111107

Question 11

What is the typical presentation of Hashimoto thyroiditis?

Answer 11

Goiter (70% of cases), often asymptomatic, may present with signs of hypothyroidism

Question 12

What is the treatment for Hashimoto thyroiditis?

Answer 12

Levothyroxine therapy, with the goal of keeping TSH between 1 and 3 µIU/mL

Question 13

What is the most common cause of hyperthyroidism in the pediatric population?

Answer 13

Graves disease

Question 14

What is the peak incidence age group for Graves disease?

Answer 14

11-15 years old

Question 15

What is the female-to-male ratio in Graves disease?

Answer 15

0.2090277777777778

Question 16

What is the initial treatment for Graves disease?

Answer 16

Antithyroid drugs (e.g., methimazole)

Question 17

What is the role of radioactive iodine (RAI) in Graves disease?

Answer 17

It is used for permanent therapy if remission is not achieved with antithyroid drugs

Question 18

What is subacute thyroiditis?

Answer 18

A self-limited inflammation of the thyroid, often following an upper respiratory tract infection

Question 19

What is the typical presentation of subacute thyroiditis?

Answer 19

Fever, pain referred to the jaw, tender thyroid gland, and symptoms of hyperthyroidism

Question 20

What is the treatment for subacute thyroiditis?

Answer 20

Anti-inflammatory medications to control pain; transient hypothyroidism may occur

Question 21

What is neonatal thyrotoxicosis?

Answer 21

Hyperthyroidism in neonates due to transplacental delivery of TSI antibodies from a mother with Graves disease

Question 22

What is the treatment for neonatal thyrotoxicosis?

Answer 22

Self-limited; may require methimazole and beta-blockers to control symptoms

Question 23

What is the most common benign thyroid nodule in children?

Answer 23

Follicular adenoma

Question 24

What is the most common type of thyroid cancer in children?

Answer 24

Papillary carcinoma (90% of childhood thyroid cancers)

Question 25

What is the diagnostic workup for thyroid nodules?

Answer 25

Thyroid function tests, neck ultrasound, fine-needle aspiration (FNA)

Question 26

What is the role of iodine-123 in thyroid imaging?

Answer 26

It is used to determine thyroid gland location and uptake

Question 27

What is the typical presentation of central hypothyroidism?

Answer 27

Signs of hypothyroidism (dry skin, constipation, cold intolerance) with normal/low TSH

Question 28

What is the treatment for central hypothyroidism?

Answer 28

Levothyroxine replacement therapy, aiming for normalization of free T4

Question 29

What is the most common cause of central hypothyroidism in children?

Answer 29

Congenital TSH deficiency (often associated with other pituitary hormone deficiencies)

Question 30

What is the typical presentation of Hashitoxicosis?

Answer 30

Transient hyperthyroidism due to release of stored thyroid hormone from Hashimoto thyroiditis

Question 31

What is the treatment for Hashitoxicosis?

Answer 31

Beta-blockers to control symptoms; it is self-limited and evolves into permanent hypothyroidism

Question 32

What is the role of TPO antibodies in Hashimoto thyroiditis?

Answer 32

They are present in >90% of cases and are a marker of autoimmune thyroiditis

Question 33

What is the typical ultrasound finding in Hashimoto thyroiditis?

Answer 33

Enlarged thyroid gland with heterogeneous echogenicity

Question 34

What is the typical presentation of subclinical hypothyroidism?

Answer 34

Elevated TSH with normal thyroid hormone levels, often asymptomatic

Question 35

What is the treatment for subclinical hypothyroidism?

Answer 35

Levothyroxine is not recommended if TSH <10 and no goiter or antibodies; consider treatment if TSH >10

Question 36

What is the typical presentation of Graves disease in children?

Answer 36

Goiter, tachycardia, weight loss, anxiety, tremors, and growth acceleration

Question 37

What is the role of thyroid receptor antibodies in Graves disease?

Answer 37

They mimic TSH action, leading to hyperthyroidism

Question 38

What is the typical presentation of neonatal thyrotoxicosis?

Answer 38

Irritability, tachycardia, poor feeding, failure to thrive, and craniosynostosis

Question 39

What is the typical presentation of thyroid-related neck mass in children?

Answer 39

Solitary thyroid nodule, often cystic and benign (70-80% of cases)

Question 40

What is the typical presentation of medullary thyroid cancer?

Answer 40

Associated with MEN 2A or 2B, elevated calcitonin levels, and RET proto-oncogene mutations

Question 41

What is the treatment for medullary thyroid cancer?

Answer 41

Surgical resection, often with prophylactic thyroidectomy in familial cases

Question 42

What is the typical presentation of congenital hypothyroidism in older children?

Answer 42

Poor linear growth, developmental delay, delayed tooth development, and hearing loss

Question 43

What is the role of newborn screening in congenital hypothyroidism?

Answer 43

It screens for elevated TSH levels, typically collected at 24-72 hours of life

Question 44

What is the typical presentation of transient hypothyroidism in neonates?

Answer 44

Caused by maternal antibodies or medications, resolves without long-term treatment

Question 45

What is the typical presentation of dyshormonogenesis?

Answer 45

Autosomal recessive disorder causing goiter due to enzyme defects in thyroid hormone synthesis

Question 46

What is the typical presentation of thyroid hormone resistance?

Answer 46

Elevated thyroid hormone levels with normal or elevated TSH, often asymptomatic

Question 47

What is the typical presentation of thyroid storm?

Answer 47

Severe hyperthyroidism with fever, tachycardia, heart failure, and altered mental status

Question 48

What is the treatment for thyroid storm?

Answer 48

Beta-blockers, antithyroid drugs, iodine, and corticosteroids

Question 49

What is the typical presentation of thyroiditis?

Answer 49

Painful or painless thyroid inflammation, often with transient hyperthyroidism followed by hypothyroidism

Question 50

What is the typical presentation of thyroid cancer in children?

Answer 50

Solitary thyroid nodule, rapid growth, hoarseness, or lymph node involvement