Thyroid gland

1. Thyroid gland

2. Thyroid gland

6. Hypothalamic -pituitary-thyroid axis:

8. Diseases of thyroid gland:

9. Thyroid masses

10. Clinical approach to a thyroid mass

21. Simple Hyperplastic Goiter 21

25. Toxic multinodular goiter: Results from disorganized response of the gland to stimulation and contains areas of hyperplasia and hypoplasia side by side. These nodules are usually necrotic and hemorrhagic. The commonest presentation is solitary nodule. The most imp. Thing to make sure that this solitary nodule is part of goiter or not by US because if not there is 20% risk of malignancy Toxic adenoma in scintigraphy:

28. Surgical treatment: * Unilateral total lobectomy * Frozen section examination * Surgery for multinodular goiter: Subtotal vs total thyroidectomy.

30. Pre-operative preparation: 1) the patient should be euthyroid to decrease the risk of arrythmia. (Give PTU +/- beta-blocker before surgery. PTU is better pre-surgical prophylaxis because it additionally blocks peripheral conversion of T4 to T3). 2) Vocal cords should be checked 3) Patient should be warned for possible nerve damage intraoperatively. 4) Warning should be giving regarding hypocalcaemia which is usually transient problem

33. Assessment of the thyroid nodule - A nodule in hyperthyroid patient is highly unlikely to be malignant. - Dominant nodule in MNG : Malignancy rate may approach that of solitary nodule 20% Size ,pain ,age ,previous neck radiation Voice changes Pressure symptoms Consistency of the nodule(hard ,fixed) Lymphadenopathy 33

34. Investigations: Hormones: T4 , T3 , TSH Neck & Chest X-ray Diagnostic investigations: Needle biopsy and FNAC Ultrasonography Isotope scanning 34

35. Treatment Hormone administration Very little evidence to affect benign nodule Indications for surgery Clinical features and suspicious or definite FNAC result. If continue enlarge despite TSH suppression Mechanical symptoms Cosmetic 35

36. Thyroid Cancer Rare: Less than 1% of all malignancies Wide spectrum of biological behavior If treated appropriately there is high survival rate Types : Papillary Follicular Anaplastic Medullary Lymphoma Rare secondary 36

37. Papillary Carcinoma The Commonest Iodine rich areas Affects children and young adults more, F>M. Previous neck irradiation It has lymphatic spread more than blood (the cervical lymph glands may be palpable long before the primary lesion in the thyroid become palpable) It could be intra, extra thyroid or multicentric. Clinical presentation: nodule with or without cervical lymphoadenopathy, voice changes, airway obstruction if enlarged. Dx: clinical assessment and FNAC 37

38. Follicular Carcinoma Higher incidence in iodine deficient areas Low association with radiation. Female to male ratio 3:1 Affects older age group Stimulated by TSH The cells in this tumor retain their normal follicular configuration, encapsulated and solitary. Spreads by blood stream to the brain, bone, lung.. It is not diagnosed by FNA Dx: frozen section Tt: total thyroidectomy. 38

39. Anaplastic carcinoma This is the worst type being poorly differentiated and highly invasive. Peak incidence 60-80 years Females more than males Rapid local tissue infiltration Rapid blood metastasis -Long standing goiter-rapid changes in voice and breathing FNAC is diagnostic Surgery, radiotherapy, chemotherapy 39

40. Treatment of differentiated thyroid carcinoma: ** Total Thyroidectomy is the treatment of choice. *Treatment objectives: Eradicate the primary tumor Reduce the incidence of metastasis Facilitate treatment of metastasis Minimal morbidity 40

41. Post operative treatment Thyroxin T4 Replacement Suppress TSH Thyroglobuline Sensitive indicator for residual or recurrent tumor Radioactive Iodine Detect metastatic disease Ablation 41