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UCLA Head and Neck Surgery Didactics September 18, 2013 Matthew K. Lee, MD Gender Female > Males 3 : 1 ratio for well differentiated Age Women: 45 – 50 Men: 65 – 70 Overall bimodal distribution of thyroid carcinoma < 20 years and > 70 years Diet Endemic goiter (iodine deficiency) and follicular / anaplastic carcinoma Radiation Low dose (< 20 Gy) Adenotonsillar Hypertrophy Acne Hemangiomas Scrofula 1/3 with radiation history have nodules ½ of these nodules harbor cancer Family History +FHx in 6% of patients Associated with Gardner’s syndrome, Cowden’s syndrome, and MEN syndromes History Increased level of suspicion in very old and very young patients Rapid growth in existing nodule is red flag Malignant degeneration or hemorrhage Exam > 2 cm higher risk of harboring cancer Palpate for goiter and substernal extension Pemberton’s Manuever Laboratory Studies TFTs Abnormal think functional disorder FNA For PTC: False negative 1%, false positive 5% 15% nondiagnostic Should not be taken as negative FNA Cannot be used to determine follicular carcinoma Histologic architecture Hurthle Cells Ultrasound Suspicious findings Microcalcifications Hypoechogenicity of solid nodule Nodes with loss of the fatty hilum Increased vascularity Rounded node configuration CT and MRI Superior for substernal extension, determining adenopathy, and tracheal invasion Wolf-Chaikoff Effect A M E S Age < 41 in M, < 51 in F Metastases Extrathryoidal Size < 5 cm Low risk Category Young, no distal mets Older, but small tumor with no extrathyroidal disease Mortality rate of 1.8%, recurrence 5% High risk Mortality rate of 46%, recurrence 55% M A C I S Metastasis Age Completeness of surgical resection Invasion of extrathyroidal tissue Size of tumor MACIS is the updated version of AGES classification Most common subtype (80%) High rates of nodal metastases 70 – 80% microscopically 15 – 30% clinically Multifocal Microcarcinoma (< 1 cm) incidentally found in contralateral lobe in up to 80% of specimens Treatment Total Thyroidectomy Central Neck Dissection only for clinically palpable nodes Prognosis 5 year OS: 95% Second most common (10%) Unifocal Hematogenous spread more common than lymphatic spread Treatment Total thyroidectomy without central neck dissection Prognosis 5 year OS: 70 – 85% Hurthle cell variant 5 year OS: 50% Derived from parafollicular C-cells (which produce calcitonin, hence amyloid) Sporadic (80%) and Familial (20%) Variants Familial = multicentric, associated with MEN or RET mutation High rate of Nodal Metastases 60 - 80% nodal involvement Least iodine avid Treatment Total Thyroidectomy with Central Neck Dissection If MEN II a/b syndrome, consider prophylactic thryoidectomy Prognosis 5 year OS: 50-80% Worse if Likely arises from transformation of well differentiated thyroid carcinoma Universally fatal Median survival < 6 months Treatment Palliative Consider tracheotomy Calcium Monitoring Thyroid Hormone Replacement Thyroid hormone replacement has two-fold purpose: Prevent symptomatic hypothyroidism Suppress TSH < 0.1 mU/L to prevent trophic effect of TSH on thyroid tumors Use Cytomel rather than Synthroid T3, Liothyronine Shorter half-life (2-3 days) to allow for RAI Mechanism of Action I-131 isotope emits B particles that penetrate and destroy tissue within 2 mm zone Patient must be in hypothyroid state in order to facilitate iodine uptake Purpose Used for PTC and Follicular (as well as MTC and Hurthle cell despite low iodine uptake) Remnant ablation (for monitoring) Adjunctive treatment of malignancy Indications Distant or nodal metastases Gross extrathyroidal extension Tumor size > 4 cm Softer indications High grade histology: tall cell, columnar, insular, and solid variants Multifocal disease > 1 cm Not indicated in: Unifocal disease < 1 cm Multifocal disease all < 1 cm Dose Typically 100 mCi (though lower doses of 30 have been used) Adverse effects 300: infertility 600: pulmonary fibrosis 900: leukemia/lymphoma, bladder cancer Other side effects: sialadenitis, nausea, neck tenderness, metallic taste Low Risk Patients Check thyroid hormone levels Check q 1 year x 2 years, then q5 years for 20 years TG should be < 2 ng/mL (if TT + RAI) If TG elevated, perform radioiodine scan High Risk Patients Regular U/S and whole body radioiodine scans q6 to 12 months MTC Calcitonin (pentagastrin stimulated) UCLA Head and Neck Surgery Didactics September 18, 2013 Matthew K. Lee, MD Regulated by the interaction of: PTH Vitamin D Calcitonin Regulated by the interaction of: Vitamin D Calcitonin PTH is immediate regulator of calcium levels Vitamin D works via GI system, and is therefore slower Explains why patients initiated on Rocaltrol do not see immediate increase in calcium levels Calcitonin Least important regulator, inhibits bone resorption Normal Dimensions 5 x 3 x 1 mm, 60 mg Fat content not reliable marker of normal versus hypercellular parathyroid Varies by patient: Women and older patients have higher fat content within parathyroid 90% of patients have 4 glands 10% can have fewer gland or supernumerary Superior Parathryoids 80% will be near the CT junction 1 cm above the intersectionof the RLN and ITA Inferior parathyroids More variable location 50% at inferior pole 30% within thyrothymic ligament or intrathymic Vascular Supply 80% of have common supply to both superior and inferior glands via the ITA 20% have superior gland supplied by the STA Rich anastomoses exist Parathyroid Adenoma Single or double Accounts for 90% of primary hyperparathyroidism Multiple Gland Hyperplasia Can be primary or secondary (renal failure) Parathyroid Carcinoma Stones Nephrolithiasis Occurs in 4% Bones Osteitis Fibrosa Cystica Incidence 1% Subperiosteal erosion, bone demineralization, Brown tumors (accumulations of osteoclasts, blasts, and fibrous matrix), pathologic fractures Groans PUD, pancreatitis, cholelithiasis, and constipation Moans Anxiety, depression, cognitive dysfunction Elevated calcium level with elevated PTH Need to rule out other causes Poor Ca / Vitamin D intake Can cause overall decrease in Ca, leading to compensatory elevation of PTH bringing serum Ca back into the normal range Familial Hypocalciuric Hypercalcemia Mutation in the calcium sensing receptor Leads to increased PTH and Ca levels Can be distinguished based on 24 hour urine calcium to creatinine clearance ratio (FHH is ratio < 0.01, have low calcium excretion relative to their serum calcium) Technetium / Thallium Imaging “Subtraction” study Technetium Sestamibi Sestamibi with SPECT CT – Sestamibi fusion U/S MRI / CT Arteriography (angio) Appears as a hypervascular mass Selective venous sampling Sample from IJ, innominate, and superior vena cava Should be twice what is in peripheral blood U/S guided FNA Indications for Surgery Serum Ca > 1 mg/dL above the upper limit Cr Clearance reduced > 30% for age 24-hour urinary Ca > 400 mg/dL. < 50 years old Bone mineral density reduced by 1 STD Patients request surgery, or patients are unsuitable for long-term surveillance Expose via similar approach as thyroidectomy If localized, can perform selective excision of adenoma Successful outcome: > 50% drop in iPTH and into normal range Non-localized 4 gland exploration If multigland hyperplasia, can perform 3 ½ gland excision versus 4 gland excision with reimplantation and cryopreservation of tissue Focused Minimal Access Approach 2 cm incision at medial border of SCM, dissect between straps and SCM Endoscopic Radioguided Surgery Tc – Sestamibi administration 2 hours prior, use handheld gamma probe