thyroid disorders dr. ali abdel-wahab. objectives upon successful completion of this lecture,...
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Thyroid Disorders
Dr. Ali Abdel-Wahab
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
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)
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
Thyrotoxicosis
It is a hypermetabolic state caused by High levels of free T3 and T4.
Constitutional symptoms: Skin soft, warm, and flushedHeat intolerance Excessive sweating Weight loss despite increased appetite
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
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
Cretinism
Hypothyroidism developing in infancy or early childhood.
Short stature, Severe mental retardation Coarse facial features Protruding tongue Umbilical hernia
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.
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)
Graves disease
Graves disease is the most common cause of endogenous hyperthyroidism.
Between ages of 20 and 40 Women: men = 7:1 Genetic factors
Graves triad:
Diffusely enlarged, hyper functional thyroid
Exophthalmos in 40%. Pretibial myxedema.
Pathogenesis
Autoimmune disorder Antibodies against
TSH receptor (Thyroid-stimulating antibodies) stimulation of thyroid epithelial cell.
Thyroid is diffusely enlarged Microscopically:
Hyperplastic thyroid follicles. Lymphocytes in the stroma.
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)
hashimoto's thyroiditis
Autoimmune destruction of the thyroid gland. Between 45 and 65 years, children may be
affected. Women: men 10 : 1 to 20 :
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).
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)
Subacute Granulomatous Thyroiditis
A self-limited a viral disease Characterized by granuloma formation of the
thyroid .
Thyroiditis:1. Autoimmune
Grave’s diseases Hashimoto's Thyroiditis
2. Subacute (Granulomatous) Thyroiditis
3.Reidel thyroditis4. Infectious thyroditis (acute and chronic)
Nodular Goiter; iodine deficiency Neoplasms
THYROID DISEASES includes(thyroid enlargement)
Reidel thyroditis
Rare disease of the thyroid characterized by diffuse fibrosis
Thyroid become hard and adherent to the surrounding structures
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)
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
Morphology
Three stages (forms)1. Diffuse goiter
2. Colloid goiter
3. Multinodular goiter.
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.
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.
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)
Tumors of the thyroid
Adenoma Carcinoma
Papillary carcinoma Follicular carcinoma. Medullary carcinoma.
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.
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.
Hyperparathyroidism
Primary; parathyroid hyperplasia or adenoma, carcinoma
Secondary; chronic renal insufficiency.
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.