2. Thyroid carcinoma Dr. Zahoor Ahmad PGR, SU-I SZMC/H. RYK, Pakisatan

3. Anatomy of Thyroid gland includes 2 lobes. Isthmus: conical or pyramidal shape.

6. Embryology• 4th week: thyroid gland appears.• 5th week: break down of the thyroglossal duct, thyroid gland continue descending• 7th week: thyroid gland migrates to its position, anterior to the trachea• 10th week: thyroglossal duct disappears

7. Anatomy Locate deep to the sternohyoid muscle, from level C5 to T1 vertebrae or anterior to the 2nd and 3rd tracheal rings. Thyroid gland is attached to the trachea by the lateral suspensory (Berry) ligaments.

8. Blood supply Blood supply: sup. & inf. thyroid arteries thyroid ima artery (1.5% to 12%)

10. pretracheal

11. paratrachealnodes.

12. Innervation:

13. superior,

14. middle,

19. Follicular cells

20. Contains colloidParafollicular cell or C-cell

24. Family history of Goiter (ret oncogene)

25. Family history of familial polyposis

26. Personal history of Autoimmune thyroiditis

27. Inheritance of oncogenes (ret/PTC1, ret/PTC3)

28. Female sex

31. Rapidly growing, Painless, palpable, irregular, solitary nodule.

32. Cervical lymph node enlargement

33. Associated symptomsNeck pain, hoarseness, dysphagia, dyspnea, stridor, hemoptysis

34. Physical Examination Thyroid gland Soft tissues of neck Solid, soft, mobile, or fixed? Tenderness? Laryngoscopy if hoarse preop!

36. Labs & investigations Baseline labs S. calcium & S. phosphate Tumor markers (S. thyroglobulin, S. calcitonin) CXR TFTs

37. Labs & investigations(cont.....) FNAC Trucut biopsy Incisional biopsy USG neck CT scan neck & thorax MRI Thyroid scan

38. Classification ofCA thyroid

39. According to origin of cell Tumors of Follicular Cell Origin Differentiated „ „ Papillary 75% „ „ Follicular 10% „ „ Hurthle Cell 5% Undifferentiated „ „ Anaplastic 5% Tumors of Parafollicular „ „ Medullary 5% „Other „ „ Lymphoma <1%

41. STAGING FOR DIFFERENTIATED STAGING FOR DIFFERENTIATED THYROID CANCER THYROID CANCER „TNM system AMES system AGES System GAMES system MACIS system University of Chicago system Ohio State University system National Thyroid Cancer Treatment Cooperative Study (NTCTCS)

42. TNM Classification Tx- size of primary tumor unknown T1- tumor size < 2 cm T2- tumor size 2-4 cm T3- tumor size >4 cm with minimal extra-thyroidal extension T4a- tumor of any size with extra-thyroidal involvement up to trachea, esophagus, larynx, RLN T4b- tumor invades paravertebral fascia, carotid artery, mediastinal lymph nodes

43. Nx- nodes not assesed N0- no nodes involved N1- node involvement up to level 1(pretracheal. Paratracheal, prelaryngeal) N2- cervical or superior mediastinal l/node involvement

44. Mx- extent of mets can not be assesed M0- no metastases M1- presence of distant mets

45. University of Chicago system An easy An easy- to-remember staging system for papillary carcinoma Class I— disease limited to the thyroid gland Class II— lymph node involvement Class III— extrathyroidal invasion Class IV — distant metastases

46. National Thyroid Cancer Treatment Cooperative Study (NTCTCS) The NTCTCS created a staging approach that was applied prospectively to a registry of patients drawn from 14 cooperating institutions . pathologic staging was based upon: „ „ patient age at diagnosis „ „ tumor histology „ „ tumor size „ „ intrathyroidalmultifocality „ „ extraglandular invasion „ „ metastases „ „ tumor differentiation

47. MAICS Scoring MAICS Scoring „ „ Developed by the Mayo Clinic for staging „ „ It is known to be the most accurate predictor of a patient's outcome patient's outcome with papillary thyroid cancer (M = Metastasis, A = Age, I = Invasion, C = Completeness of (M = Metastasis, A = Age, I = Invasion, C = Completeness of Resection, S = Size) Resection, S = Size) MAICS Score MAICS Score 20 year Survival 20 year Survival <6 <6 = = 99% 99% 6 6- -7 7 = = 89% 89% 7 7- -8 8 = = 56% 56% >8 >8 = = 24% 24%P

48. Papillary Carcinoma Most common (80%) Women 3 times more common 30-40 years of age Familial also Radiation exposure as a child Patients with Hashimoto’s thyroiditis Slow growing, TSH sensitive, take up iodine, TSH stimulation produces thryroglobulin response.

49. Papillary Carcinoma Pathology:Unencapsulated, arborizing papillae. Well differentiated, rare mitoses. 50% have psammoma bodies (calcific concretions, circular laminations. Multicentric with tumor present in contralateral lobe as well.

50. Papillary Carcinoma Local invasion through capsule, invading trachea, nerve, causing dyspnea, hoarseness. Propensity to spread to the cervical lymph nodes. Clinically evident in 1/3 patients. Most commonly central compartment, located medial to carotids, from hyoid to sternal notch. Distant spread to bone, lungs.

52. Follicular Carcinoma Second most common (10%) Iodine deficient areas 3 times more in women Present more advanced in stage than papillary Late 40’s Also TSH sensitive, takes up iodine, produces thryroglobulin.

53. Follicular Carcinoma Pathology: round, encapsulated, cystic changes, fibrosis, hemorrhages. Microscopically, neoplastic follicular cells. Differentiated from follicular adenomas by the presence of capsule invasion, vascular invasion. Cannot reliably diagnose basedon FNA.

55. Follicular Carcinoma Local invasion is similar to papillary cancer with the same presentation. Cervical metastases are uncommon. Distant metastases is significantly higher (20%), with lung and bone most common sites.

56. Treatment and Prognosis Controversy regarding extent of therapy continues. Surgical excision whenever possible. Total thyroidectomy has been mainstay (all apparent thyroid tissue removed). Complications include nerve damage bilaterally, parathyroid injury bilaterally. After, get radioiodine scan, ablation if residual disease or recurrence.

57. Treatment and Prognosis Over the years, modification to procedure to reduce the above complications. Subtotal thyroidectomy( small portion of thyroid tissue opposite the side of malignancy is left in place) and postop ablation. Thyroid lobectomy and isthmectomy also a viable option with small tumors

58. Neck Examine the neck prior to surgery to detect lymph node spread. Gross cervical mets should be removed en bloc with a dissection in the compartment in which they reside. Excision of single nodes is not adequate. Elective lymph node dissection is not done, as radioactive iodine takes care of this.

59. Postoperative Radioiodine and Ablation Radioiodine targets residual thyroid tissue and tumor after thyroidectomy. Given in diagnostic doses and therapeutic doses to ablate tissue.

60. Thyroid Suppression Therapy Maintained on thyroxine after surgery and ablation. Low TSH levels reduce tumor growth rates and reduce recurrence rates. Most recommend TSH levels of 0.1 mU/l. Follow-up q 6 months with thyroglobulin levels and repeat scans. Thyroglobulin is good because well differentiated tumors produce it.

62. Recurrences common in patients diagnosed when they were less than 20 years or olderthan 60 years.

63. Men are twice more likely as women to die.

65. Local invasion portends poorer prognosis.

66. After surgery, thyroxine is given. Do I scanning after stopping it for 6 weeks, TSH high now. Do scan, if some tissue remains on diagnostic dose, ablate it. Do it again if needed.

67. LN metastases not important for prognosis.

69. More common in women than men, presents in 5th decade of life.

70. Same clinical presentation.

71. Cannot diagnose on FNA

72. Does not take up iodine, so treat aggressively.

75. MEN 2b is MTC, pheo, ganglionomas, marfan habitus.

76. FMTC is just MTC

77. Medullary cancer in these are most aggressive, younger age, rapid growth and metastases.

79. Treatment Total thyroidectomy Lymph node dissection of level VI. Parathyroid reimplantation if necessary. Lymph node mets are very common. Prophylactic thyroidectomy in children with MEN 2a,b. Surveillance with CEA, calcitonin. Does not take up iodine, so no radioiodine. Prognosis 10 y is 65%.

80. Anaplastic Thyroid Carcinoma Bad.

81. Indications for Thyroid Lobectomy Suspicion for malignancy Compressive symptoms Cosmetic issues Patient wishes Well-differentiated thyroid carcinoma in low risk patient (controversial)

82. Indications for Total Thyroidectomy Well-differentiated thyroid cancer Medullary thyroid cancer Sarcoma of thyroid Lymphoma of thyroid Obstructive goiter