1. Causes Thyroid swelling:  Hyperthyroidism.  Hypothyroidism.  Non – toxic goitre.  Auto – immune thyroid disease.  Thyroiditis both local and chronic.  Thyroid tumour : adenoma and carinoma.

2. Thyroid hormones and functions:  Thyroxine T4.  Tri aodothyronine T3.  Calcitonin.  T4 and T3 are needed by all cells for metabolism process.  Calcitonin : regulate serum calcium by lowering its level.

3. Non – toxic nodular goitre. :  It is the commonest lesion in thyroid pathology and reflects compenesatory thyroid hyperplasia because of absolute or relative iodine deficiency.  Goitre can be endemic or sporadic

4. Endemic goitre:  Occurs in children and less in female.  Occurs in mountinainous areas. or in areas far from sea e.g. Gebel Mara.  Sporadic non –toxic goitre  Causes :  Due to relative lack of iodine in individuals Patients.  Could be due to poor dietary intake  Or from inherited deficiency of the various enzymes involved in the biosynthesis of T4.

5.  Or from ingestion of specific chemicals e.g. :cabbage, excessive fluoride in water more common in females.  It presents at puberty or at pregnancy and lactation.

6.  Clinical presentation:  Clinicaly patient is euthyroid with a slight increase in TSH  It can be colloid goitre.or multinodular goitre. It may compress the recurrent laryngeal nerve causing coarse voice or trachea causing difficult breathing.  Or the oesophageal cause dysphagia.  Cosmotic  Become toxic.

7. Auto immune thyroid disease include”:  Hashimoto.  Primary myxoedema.  Graves dis.

8. Characterised by:  The presence of circulating auto antibodies the various components of thyroid follicular cells.  These play an active role in the pathogenesis of the dis.  Thyroid stimulating immunoglobulins (TSI)  TSH receptor antibodies results in hyperthyroidism (Graves dis.)while blocking antibodies with TSH receptor contribute to hypothyroidism primary myxoedema and Hashimoto s dis.

9. Thyrid tumour :  Can occur from both follicular epithelial and C cells.  Majority are follicular adenoma.  Malignant tumour divided into:  Papillary and follicular carinoma.  Medullary carinoma from C cells.

10. Follicular Adenoma:  Seen in women over 30 yrs may cause hyperthyrodism (toxic adenoma)  Encapsulated and compress the surrounding normal gland.  Hemorrhage, degenerative changes and fibrosis.

11. Papillary carcinoma:  60 – 70 % occur in young adults(30 – 40) yrs.  More common in female.  It spreads by lymphatic.  Size is small can be known by enlarged lymph node. Follicular carcinoma:  15 – 20 % of all thyroid cancers but in areas of endemic goitre.