Surgical Aspects of Thyroid Tumours.pptx

Surgical Aspects of Thyroid Tumours

1. Surgical Aspects of Thyroid Tumours Department of ENT and Head & Neck Surgery Dr Shubham Dadoo

2. INTRODUCTION Thyroid cancer is most common endocrine tumour . Incidence 1.2-3.8 / 1 Lakh cases/ Yr. M/C Presentation – Solitary thyroid nodule in a euthyroid Pt. 2-4 times more frequent in females. Rare in children below 16 yrs

3. Predisposing FACTORS prolonged stimulation by elevated TSH; solitary thyroid nodule; ionizing radiation; genetic factors; chronic lymphocytic thyroiditis .

4. A nodule is more likely to be malignant if: there is a previous history of thyroid cancer; it is enlarging (particularly on suppressive doses of thyroxine ); the nodule develops under 14 or over 65 years of age; the patient is male; there is a past history of ionizing radiation; TSH is elevated; thyroid antibodies are positive.

5. a) Rapid tumour growth. b) Very firm nodules. c) Fixation to adjacent structures. d) Vocal cord paralysis. e) Regional LAP. f) Family history of MTC or MEN. g) Age <20 or >60 years. h) Male sex. i ) Solitary nodule. j) Elevated TSH. k) History of head or neck irradiation. l) Compression symptoms: dysphagia , dysphonia , hoarseness, dyspnoea or cough. Factors suggesting the diagnosis of thyroid carcinoma in patients presenting with thyroid enlargement

6. CLASSIFICATION OF THYROID TUMOURS BENIGN A) Follicular cell adenoma. B) Hurthle cell adenoma. C) Teratoma . SECONDARY: MALIGNANT PRIMARY Papillary carcinoma - Pure papillary. - Mixed papillary-follicular. - Follicular variant. Follicular carcinoma Hurthle cell carcinoma Medullary carcinoma Anaplastic carcinoma Lymphoma Sarcoma Squamous cell carcinoma SECONDARY Kidney, Lung, Colon & Breast

7. PAPILLARY ADENOCA 80% of thyroid malignancy. Occurs in all age groups. Presents as solitary nodule in thyroid. EXTENT – a) Minimal ( microCa ) <1.0 cm b) Intra-thyroidal >1.0 cm c) Extra-thyroidal- beyond gland capsule and/or with lymph node metastases. Young adults (20-45 yrs) Female to male ratio is 3:1. High incidence of involvement of cervical lymph nodes(60%) in levels 3 to 7

8. FOLLICULAR ADENOCA Occurs in older age groups. Most common in 50-59 yrs. 10 – 20 % of all thyroid malignancies. Most commonly presents as a solitary thyroid nodule. Lymph node involvement is much less common (about 10%)

9. HURTHLE CELL TUMOURS Extremely uncommon. Histological distinction between benign and malignant is difficult. Malignant invade surrounding thyroid tissue and extrathyroid structures. Lymph node metastases are common.

10. MEDULLARY THYROID CA 5% of all cases of thyroid malignancy. Occur as a part of MEN syndrome, as familial non-MEN disease or it may be sporadic. In patients with MEN, it is frequently multifocal and bilateral (90%). Cervical node metastases in 50% of cases.

11. ANAPLASTIC CARCINOMA More common in elderly and in women. Superimposed on a long standing goitre . Increases in size rapidly. Associated with otalgia , hoarseness and stridor . Aggresively malignant, high metastatic potential. BAD prognosis.

12. INVESTIGATION PROFILE INCLUDES- 1) Radiology. 2) Laboratory investigations. 3) Cytology.

13. DIAGNOSTIC STRATEGY FOR EVALUATION OF ‘SOLITARY’ THYROID NODULE Physical examination + Thyroid function tests Treat thyroid dysfunction Refer for FNAC if no if present. thyroid dysfunction FNAC Results Malignant Suspicious Benign Inadequate sample Surgery Surgery Repeat FNAC Repeat after 6 months FNAC

14. LABORATORY INVESTIGATIONS INCLUDE: a) TSH b) T3 c) T4 d) Serum calcium e) Thyroid f) If medullary carcinoma is suspected, serum calcitonin should be measured.

15. CYTOLOGY FNAC- gold standard investigation. FNAC SHOULD NOT BE RELIED UPON IN PATIENTS WITH A HISTORY OF RADIATION EXPOSURE TO EXCLDE THE MALIGNANCY. INSTEAD NEEDLE-CORE BIOPSY IS APPROPRIATE.

16. Patients under 45 and women in general have a better prognosis. Patients with papillary thyroid cancer have better prognosis than other thyroid tumours . Nodal metastases are associated with worse prognosis in elderly patients. For medullary thyroid cancers, age at presentation,TNM staging, previous surgery, extent of surgery, pre and post-op calcitonin levels are important prognostic factors. PROGNOSTIC FACTORS

17. TREATMENT POLICY Treatment modalities for thyroid malignancy include: Surgery. Radioactive iodine. External beam radiotherapy. Thyroxine therapy. Chemotherapy.

18. SURGERY is the mainstay of treatment Main aim of initial therapy: - remove the primary tumour disease and that which has spread to the thyroid gland capsule and involved cervical lymph nodes. SURGICAL MANAGEMENT

19. Total thyroidectomy = 2 × total lobectomy + isthmusectomy Subtotal thyroidectomy = 2 subtotal lobectomy + isthmusectomy Near-total thyroidectomy = total lobectomy + isthmusectomy + subtotal lobectomy Lobectomy = total lobectomy + isthmusectomy

20. NECK DISSECTION IN THYROID CANCER Elective neck dissection is not performed for DTC of follicular cell origin Central compartmental ( level VI) is recommended for all patients with clinically involved nodes Prophylactic central neck dissection in clinically N0 patients with T3 or T4 tumors

21. PAPILLARY THYROID CANCER Cancer <=1cm with N  LOBECTOMY and THYROXINE SUPPRESSION THERAPY. B) Cancer >1 cm in diameter / Multifocal disease / History of previous radiation exposure in childhood  TOTAL THYROIDECTOMY.

22. FOLLICULAR THYROID CARCINOMA <1 cm in diameter and no capsular invasion  ONLY LOBECTOMY. Follicular carcinoma with evidence of vascular invasion  TOTAL THYROIDECTOMY. 3) > 4 cm in diameter- TOTAL OR NEAR-TOTAL THYROIDECTOMY.

23. SOLITARY THYROID NODULE FOLLICULAR LESION (Thy 3)- Diagnostic hemithyroidectomy . SUSPICIOUS FOR CARCINOMA (Thy 4)- Diagnostic hemithyroidectomy with or without complete frozen section and proceed. PAPILLARY CARCINOMA (Thy 5)- Total thyroidectomy with or without neck dissection and central neck dissection in high risk patients. MEDULLARY CARCINOMA (Thy 5)- Total thyroidectomy and level 6 + 7 dissection and lateral neck dissection in high risk patients.

24. POSTOP CARE In immediate post-op period  watch for bleeding and airway embarassment . Blood count and serum calcium the morning after surgery. Following lobectomy  T hyroxine replacement not required unless patient develops subclinical hypothyroidism. TFT performed  6 weeks after surgery. e) Following lobectomy for malignancy  suppressive doses of thyroxine f) After total thyroidectomy for malignancy , commence T4 immediately unless radioiodine ablation is planned within next four weeks

25. ADJUVANT THERAPIES RADIOACTIVE IODINE – - The usual ablation dose is 3GBq. - A post ablation scan should be performed 3-5 days following the ablation dose.

26. 2) EXTERNAL BEAM RADIOTHERAPY- Indications: a) Primary treatment. b) High risk of loco-regional recurrence(patients with extensive extrathyroid invasion and extranodal extension). c) Local invasion. d) Residual micro/macroscopic disease. e) Refusal or allergy to RAI2. f) Solitary osseous metastasis. g) Focus of poorly differentiated / anaplastic carcinoma in the resected specimen.

27. 3) THYROXINE SUPPRESSION THERAPY- evidence that doses of thyroxine adequate to suppress TSH increase recurrence-free survival in patients with DTC .

28. COMPLICATIONS FOLLOWING THYROIDECTOMY EARLY : Haemorrhage , voice change, airway obstruction and temporary hypoparathyroidism . INTERMEDIATE: Seroma formation, infection and temporary palsy of RLN and External branch of SLN. LATE: Subclinical hypothyroidism, permanent hypoparathyroidism , permanent injury to RLN, EBSLN, cutaneous nerves C2 and C3 and the accessory nerve and a poor scar.

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