1. Thyroid Disorders Dr. Ali Abdel-Wahab

2. Objectives Upon successful completion of this lecture, students will be able to: Recognize the clinical picture & Laboratory findings of hyperfunction and hypofunction of thyroid gland Enumerate causes of hypofunction and hyperfunction of thyroid gland Discuss cretinism and myxedema List the causes of thyroid enargment Discuss the Pathogenesis of grave’s disease Discuss the Morphology of noduar goiter Discuss the complication of nodular goiter Mention the types and clinical picture of hyperparathyroidism

3. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms Adenoma Carcinoma THYROID DISEASES includes (thyroid enlargement)

4. Thyroid hormone disturbances Hypothyroidism  Cretinism  Myxedema. Hyperthyroidism  Primary thyrotoxicosis (Graves disease).  Secondary thyrotoxicosis;  Complication of nodular goiter  Early Hasimoto’s thyroiditis  Thyroid tumor  Pituitary disorders  Extrathyroid thyroxin producing tumors

5. Thyrotoxicosis It is a hypermetabolic state caused by High levels of free T3 and T4. Constitutional symptoms: Skin soft, warm, and flushed Heat intolerance Excessive sweating Weight loss despite increased appetite

6. Manifestations Cardiovascular Palpitations and tachycardia congestive heart failure Ocular manifestations: Staring gaze and lid lag Proptosis in Graves disease. GIT Hypermotility Malabsorption Diarrhea. Thyroid storm abrupt onset of severe hyperthyroidism during stress. Apathetic hyperthyroidism Elderly Associated disease

7. Hypothyroidism Types primary; thyroid diseases Secondary; pituitary (TSH) Clinically Cretinism Dietary iodine deficiency is endemic; Maternal hypothyroidism Inborn errors in metabolism Myxedema Autoimmune Thyroid destruction, radiation, surgery

8. Cretinism Hypothyroidism developing in infancy or early childhood. Short stature, Severe mental retardation Coarse facial features Protruding tongue Umbilical hernia

9. Myxedema Generalized apathy Mental sluggish ( depression). Cold intolerant Often overweight Edema (Mucopolysaccharide) Broadening and coarsening of facial features Enlargement of the tongue Deepening of the voice. GIT Constipation. CVS Pericardial effusions Later stages the heart is enlarged & heart failure.

11. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms THYROID DISEASES includes (thyroid enlargement)

12. Graves disease Graves disease is the most common cause of endogenous hyperthyroidism. Between ages of 20 and 40 Women: men = 7:1 Genetic factors

13. Graves triad: Diffusely enlarged, hyper functional thyroid Exophthalmos in 40%. Pretibial myxedema.

14. Pathogenesis Autoimmune disorder Antibodies against TSH receptor (Thyroid-stimulating antibodies) stimulation of thyroid epithelial cell.

15. Thyroid is diffusely enlarged Microscopically: Hyperplastic thyroid follicles. Lymphocytes in the stroma.

16. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms THYROID DISEASES includes (thyroid enlargement)

17. hashimoto's thyroiditis Autoimmune destruction of the thyroid gland. Between 45 and 65 years, children may be affected. Women: men 10 : 1 to 20 :

18. Morphology Diffusely and symmetrically enlarged thyroid lymphocytes, plasma cells, and well- developed germinal centers (red arrow). The thyroid follicles are atrophic with Hürthle metaplasia (green arrow).

19. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms THYROID DISEASES includes (thyroid enlargement)

20. Subacute Granulomatous Thyroiditis A self-limited a viral disease Characterized by granuloma formation of the thyroid.

21. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms THYROID DISEASES includes (thyroid enlargement)

22. Reidel thyroditis Rare disease of the thyroid characterized by diffuse fibrosis Thyroid become hard and adherent to the surrounding structures

23. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms THYROID DISEASES includes (thyroid enlargement)

24. Types of nodular Goiter Endemic goiter; areas where the soil, water, and food supply contain little iodine.  >10% of the population affected by goiter Sporadic goiter occurs less commonly Females A peak incidence in puberty or young adult life Causes Relative iodine deficiency ingestion of substances that interfere with thyroid hormone synthesis  Excessive calcium  Diet; cabbage, cauliflower  Contaminated water

25. Morphology Three stages (forms) 1. Diffuse goiter 2. Colloid goiter 3. Multinodular goiter.

26. Pathogenesis Impairment of thyroxin synthesis leads to A compensatory rise in the serum TSH, TSH causes hypertrophy and hyperplasia of thyroid A euthyroid metabolic state in the majority of individuals The compensatory responses may be inadequate; goitrous hypothyroidism., disorder is severe The degree of thyroid enlargement is proportional to the level and duration of thyroid hormone deficiency.

27. Clinically Enlarged thyroid gland Compression Airway obstruction Dysphagia Compression of large vessels in the neck and upper thorax. Thyroxin level Euthyroid Toxic goiter a minority Hypothyroidism.

28. Thyroiditis: 1. Autoimmune  Grave’s diseases  Hashimoto's Thyroiditis 2. Subacute (Granulomatous) Thyroiditis 3. Reidel thyroditis 4. Infectious thyroditis (acute and chronic) Nodular Goiter; iodine deficiency Neoplasms Adenoma Carcinoma THYROID DISEASES includes (thyroid enlargement)

29. Tumors of the thyroid Adenoma Carcinoma Papillary carcinoma Follicular carcinoma. Medullary carcinoma.

30. Causes of thyroid carcinoma Ionizing radiation first 2 decades of life radiation therapy 9% Among atomic bomb survivors in Japan nuclear plant disaster; Chernobyl. Long-standing multinodular goiter.

31. Types of thyroid carcinoma 1. Papillary thyroid carcinoma; common, young, lymphatic spread 2. Follicular carcinoma; adult, blood spread, bone. 3. Medullary carcinoma; parafollicular cell, secrete calcitonin.

33. Hyperparathyroidism Primary; parathyroid hyperplasia or adenoma, carcinoma Secondary; chronic renal insufficiency.

34. Hyperparathyroidism Effects Osteoclast activation. Increased resorption of calcium by the renal tubules Increased urinary excretion of phosphates Increased synthesis of active vitamin D The net result is an elevation in serum calcium, which, under normal circumstances, inhibits further PTH production.