بسم الله الرحمن الرحيم

THYROID GLAND

By Dr. Ghada Ahmed

Lecturer of pathologyBenha Faculty of Medicine

Normal thyroid

Hypothalamic-pituitary-thyroid axis

Hypothyroidism Primary hypothyroidism Thyroiditis :Hashimoto autoimmune

thyroiditis Dietary iodine deficiency. Drugs that block thyroid hormone

synthesis. Thyroid surgery or radiation.

Secondary hypothyroidism: usually caused by TSH deficiency.

Hypothyroidism

Clinical effects:

Cretinism

Hypothyroidism

Myxdema

Hyperthyroidisim (Thyrotoxicosis)

Primary hyperthyroidism: Graves disease (autoimmune)(85% of cases). Goiter: Hyperfunctional multinodular goiter. Adenoma: Hyperfunctional adenoma of

thyroid.

Secondary hyperthyroidism: Pituitary adenoma. Inappropriate intake of exogenous hormone

(as a treatment for hypothyroidism)

Hyperthyroidisim (Thyrotoxicosis)Clinical features:

Cardiac manifestations Ocular manifestations Neuromuscular system Skin Gastrointestinal system Low serum TSH with increased free serum T4.

Thyroiditis

Types: Hashimoto thyroiditis Subacute (granulomatous)

thyroiditis Reidel thyroiditis

Hashimoto thyroiditis

Hashimoto thyroiditis

Subacute (granulomatous) thyroiditis

History of upper respiratory tract infection

Reidel thyroiditis

Rare disease. Unknown etiology. Extensive fibrosis of thyroid and

surrounding neck structures.

Graves disease

Pathogenesis It results from autoantibodies to

TSH receptor, (long acting thyroid stimulator (LATS)) activate the surface receptors for TSH on thyroid epithelium.

Graves disease

Pathogenesis Gross picture Microscopic picture

Graves disease

Graves disease

Clinical effects

Goiters Definition

Goitrogens

Types of Goiter

Goiter

Diffuse(non toxic)

Endemic

Sporadic

Multinodular(toxic / non toxic)

Diffuse nontoxic (simple) goiter

Endemic form Sporadic form

Morphology: Hyperplastic stage Colloid involution stage Most patients are clinically

euthyroid.

Multinodular goiter (Nodular colloid goiter)

Repeated cycles of stimulation and involution of a diffuse goiter

Pressure symptoms It may be non-toxic or may induce

thyrotoxicosis (toxic multinodular goiter).

Multinodular goiter (Nodular colloid goiter)

Multinodular goiter (Nodular colloid goiter)

Tumors of the thyroid gland

A) Benign tumors:Follicular adenoma

B) Malignant tumorsThyroid carcinoma

Benign tumorsthyroid follicular adenoma

Benign tumorsthyroid follicular adenoma

Microscopic picture: various histologic subtypes according to degree of follicle formation and colloid content:

1- Colloid adenoma (macrofollicular).

2- Fetal adenoma (microfollicular). 3- Embryonal adenoma. 4- Hϋrthle cell adenoma. 5- Atypical adnoma.

Benign tumorsthyroid follicular adenoma

Thyroid follicular adenoma

Clinical effects:

Thyroid carcinoma

Papilary carcinoma Follicular carcinoma Medullary carcinoma Anaplastic carcinoma

Papillary carcinoma

Papillary carcinoma

Follicular carcinoma

Follicular carcinoma

Capsular invasion in follicular carcinoma

Vascular invasion in follicular carcinoma

Medullary carcinoma

Medullary carcinoma

Anaplastic carcinoma

Anaplastic carcinoma

Thyroid Nodule

Thyroid nodule

Non-neoplastic

Nodular colloid goiter

Hashimoto thyroiditis

Neoplastic

Adenoma carcinomas

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