PEDIATRIC THYROID MALIGNACY Anthony Sheyn MD Assistant Professor of Otolaryngology Head and Neck Surgery University of Tennessee Health Science Center
Thyroid nodules 20 per 1000 children nodules in children carry a greater risk of malignancy compared to those in adults (22% 26% versus 5% 10% in most series) Thyroid cancer patients < 20 years = 1.8% of all thyroid malignancies in US 3.7% of school-aged children in the US with thyroid disease ½ are diffuse gland hypertrophy or simple goiter 2nd most common is thyroiditis 3rd most common is thyroid nodules Malignant neoplasms are rare INCIDENCE
Thyroid nodules less common among children than adults but more likely to be malignant Estimates from US and postmortem examination 1% 1.5% of children and up to 13% of older adolescents or young adults have thyroid nodules Risks factors iodine deficiency, prior radiation exposure, a history of antecedent thyroid disease and several genetic syndromes develop in cancer survivors at a rate of about 2% annually and reach a peak incidence 15 25 years after exposure Patients in ACT clinic (long term St. Jude follow-up) receive a thyroid ultrasound 6-12 months
Papillary Classic, Solid, Diffuse sclerosing, Tall cell, Hobnail Follicular Mixed Anaplastic Medullary Lymphoma THYROID MALIGNANCY
Represents 3% of pediatric malignancies Thyroid cancer among 15 to 19-year-old adolescents 8th most frequently diagnosed cancer 2nd most common cancer among girls Girls:Boys 2:1 predominance Adolescents have a 10-fold greater incidence than younger children there is a female to male preponderance (5:1) during adolescence THYROID CARCINOMA
Associated with RAS proto-oncogene mutations (20% of papillary and 80% of follicular tumors) Mutation of the RET proto-oncogene is found in 35% of papillary thyroid cancer RET protein also shown to have a role in medullary thyroid cancer Regional lymph nodes metastasis found at diagnosis in 3:4 children Bilateral as often as 66% of cases THYROID CARCINOMA
EVALUATION
Focused History Symptoms of hyperthyroidism or hypothyroidism Compressive symptoms: Dysphonia, dysphagia, dyspnea Family history of thyroid disease or genetic syndrome History of radiation or chemotherapy EVALUATION OF THE THYROID GLAND
Detailed examination of the neck Evaluate size, consistency, symmetry & whether there are any nodules or associated enlarged lymph nodes A tender gland can be found with an acute inflammatory process, multiple nodules are more common in a metabolic or inflammatory process A single nodule is more likely to be neoplastic. rapid growth, hardness, fixation to surrounding structures, and enlarged cervical nodes. An annual physical examination is recommended in children at high risk for thyroid neoplasia. EVALUATION OF THE THYROID GLAND
Solitary vs Multinodular Nodules > 4 cm in size Firmness to palpation Significant fixation to surrounding tissues Associated lymphadenopathy in the central or lateral cervical compartments Objective hoarseness & ipsilateral RLN paralysis PHYSICAL EXAM FINDINGS CONCERNING FOR MALIGNANCY
TSH Free T4 and T3 most sensitive test for detecting autoimmune thyroid disease Thyroglobulin improve ability to detect thyroid dysfunction in the presence of thyroid hormone-binding abnormalities Thyroid Autoantibodies most sensitive method for detecting thyroid dysfunction reflective of thyroid tissue present, presence of injury or inflammation of the gland and the degree of stimulation of the TSH receptor Calcitonin tumor marker for MTC DIAGNOSTICS
Ultrasound CT Neck Include lateral neck when dealing with carcinoma Usually not needed unless tracheal involvement suspected CT Chest/Chest X-ray If pulmonary metastases suspected Use Non-iodinated contrast IMAGING
Cornerstone of diagnostic evaluation of the thyroid nodule. Identify Benign and malignant follicular and Hurthle cell adenomas and carcinomas cannot be distinguished on the basis of cytology colloid nodules, benign nodular hyperplasia, thyroiditis, papillary thyroid carcinoma, medullary thyroid carcinoma and anaplastic thyroid carcinoma as tissue architecture is required through observation of capsular or angiolymphatic invasion. In high risk children with nondiagnostic result Hemithyroidectomy is recommended FINE NEEDLE ASPIRATION BIOPSY
80% of thyroid cancers >90% of childhood cases Female predominance More common in iodine-sufficient areas Major risk factor radiation exposure Histologic variants Children < 5yo most sensitive classic, solid, follicular, and diffuse sclerosing Diffuse thyroid enlargement PAPILLARY THYROID CARCINOMA
Arises from follicular cells Papillary architecture Calcifications Psammoma bodies Squamous metaplasia Fibrosis Orphan Annie nuclei Intranuclear grooves PTC HISTOLOGY
Excellent survival 30% Bilateral; 65% Multifocal Our series about 41% bilareral (18/43) Lymphatic spread 30-40% LN positive More likely in children Distant metastases in 2-14% 95% at 5 years Lung most common 70% are sensitive to RAI PTC PROGNOSIS
Comprehensive neck ultrasound in addition to thyroid ultrasound FNA suspicious lymph nodes CND recommended in children with malignant histology AND clinical evidence of extrathyroidal invasion AND/OR locoregional metastases TT recommended for majority of children Higher incidence of bilateral and multifocal disease Our series all patients with malignancy had total or completion thyroidectomy Prophylactic neck dissection not recommended Evidence of metastatic disease should result in lateral neck dissections However, pediatric disease is more aggressive and further study needed to determine need for more aggressive surgery KEY TREATMENT POINTS
Architecture of follicular ca Cytologic appearance of papillary ca Follicular lesion by frozen section Atypical and invasive on final pathology Prognosis and treatment similar to papillary ca FOLLICULAR VARIANT
Less than 1cm 0.4% cause-specific mortality If found after lobectomy, no further treatment indicated If found preoperatively, can remove or follow 70% will not increase in size significantly Consider as source if positive central LN found without clear primary PAPILLARY MICROCARCINOMA
10-20% of thyroid cancers Female predominance More common in iodinedeficient areas (Great Lakes Region) 10% chance if FNA shows follicular cells FOLLICULAR CARCINOMA
Follicular lesion with vascular or capsular invasion Delimited by a fibrous capsule surrounding tightly packed follicles, trabeculae or solid sheets of tumor cells Often cuboidal with dark or pale staining nuclei with inconspicuous nucleoli Lack features of papillary tumors FTC HISTOLOGY
Usually solitary Hematogenous spread Only 10% LN involvement When matched for stage, prognosis similar to that of papillary 80% sensitive to RAI FTC PROGNOSIS
Capsular invasion without vascular invasion If found on lobectomy, no further resection needed Would perform RAI scan to look for spread MINIMALLY INVASIVE FOLLICULAR CARCINOMA
Lobectomy Total thyroidectomy Lymphadenectomy Radioactive iodine External beam radiation TSH suppression therapy Chemotherapy TREATMENT OPTIONS
PAPILLARY CARCINOMA FOLLICULAR CARCINOMA Age 15-45 Minimally invasive Tumor < 4cm No radiation hx Initial evaluation of follicular lesion on FNA No metastases or extension Non-aggressive variant INDICATIONS FOR LOBECTOMY
PAPILLARY CARCINOMA Age <15 or >45 Radiation hx Known metastases Bilateral nodularity Aggressive variant FOLLICULAR CARCINOMA Vascular invasion on histology Tall cell, columnar cell, poorly differentiated Lobectomy with positive margins, multifocal disease, or vascular invasion INDICATIONS FOR TOTAL THYROIDECTOMY
Clinically or biopsy positive nodes Central neck (level VI) Lateral neck (levels II, III, IV, Vb) If aggressive tumor, consider prophylactic central neck dissection (level VI) INDICATIONS FOR NECK DISSECTION
Ensure airway patency, check for hematoma Check calcium level (ionized or total), PTH in PACU One of the most common complications in children (nearly 20%) and no hypocalcemia protocol exists yet Supplemental calcium Check voice quality and post-operative laryngoscopy RAI if indicated TFT measurement at 6 months POST-OPERATIVE CARE
Pre-operative Complete metabolic panel Mg2+ Vitamin D if low supplements start prior to surgery Peri-operative PACU PTH level Post-operative All patients should be on telemetry CURRENT HYPOCALCEMIA PROTOCOL
Low Risk Patient Completion thyroidectomy or Total thyroidectomy without central neck dissection PTH level in PACU If PTH < 10 pg/ml If PTH > 10 pg/ml Anticipate low serum calcium and proceed with high risk protocol Two Ca2+ draws > 8.8 mg/dl Stop Lab draws If PTH > 10 pg/ml and Ca2+ < 8.8 mg/dl Start PO Calcium Carbonate 1000 mg TID POST-OPERATIVE HYPOCALCEMIA MANAGEMENT
High Risk Patient Central Neck dissection or re-operation with parathyroid re-implantation PTH in PACU, Ca2+ q4h x 2 and if normal can go to q6h PTH < 10 pg/ml PO Calcium Carbonate 1000 mg TID + Calcitriol 0.25 mcg BID PTH > 10 pg/ml and Ca2+ > 8.8 x 2 stop lab draws POST-OPERATIVE HYPOCALCEMIA MANAGEMENT
If PTH > 10 pg/ml and Ca2+ < 8.8 mg/dl Start PO Calcium Carbonate 1000 mg TID Calcium continues to be 8 8.8, asymptomatic continue PO supplement Calcium is 7.5 8. asymptomatic increase Calcium Carbonate to QID Calcium is < 7.5, asymptomatic EKG, Calcium gluconate 10% 2mg/mL mixed in 1 L D5 1/2NS infusing at 20 ml/hr, check Ca2+ q4h Calcium < 7.0 and symptomatic Calcium IV infusion and call ENT to bedside to evaluate for need to transfer to PICU POST-OPERATIVE HYPOCALCEMIA MANAGEMENT
Goals for discharge: Calcium > 7.8 over 12 hours on two different blood draws while off IV calcium for 8 hours
Signs/symptoms of mild to moderate hypocalcemia: Parasthesias and numbness of fingertips and perioral region Muscle stiffness, myalgias, spasms Chvostek s sign twitching of facial muscles when tapping on CN VII Trousseau s sign: carpal spasm can be induced by BP cuff Prolonger QT on EKG RESIDENT EDUCATION ON HYPOCALCEMIA SIGNS
Severe Hypocalcemia signs: Stridor/dyspnea prolonged contraction of respiratory and laryngeal muscles Anxiety, agitation, mental status changes, seizures Arrythmia on EKG RESIDENT EDUCATION ON HYPOCALCEMIA SIGNS
Staging performed 12 weeks after surgery Diagnostic whole body scan should be reserved for intermediate and high risk patients based on ATA criteria POST-OPERATIVE EVALUATION
STAGING TNM CLASSIFICATION
STAGING
Gross extrathyroidal extension Nodal and locoregional disease not amenable to further surgery Distant metastases (Pulmonary) INDICATIONS FOR RAI
No IV iodine-based contrast within 6 weeks Cannot be pregnant or nursing Usually given 6 weeks after surgery TSH should be > 30 Give T3 until 2 weeks before scan CONSIDERATIONS FOR RAI
Indications Gross residual disease with failure of RAI Palliation Great for bone and CNS involvement Contraindications Pregnancy Previous XRT Some connective tissue diseases CONSIDERATIONS FOR XRT
Keep clinically euthyroid Levothyroxine (Synthroid T4) Approximately 1.6 mcg/kg body weight per day (112 mcg/day in a 70-kg adult) Wait 6 weeks for adjustments Liothronine (Cytomel T3) 25mcg = 100mcg of T4 Wait 2 weeks for adjustments Suppress TSH to less than normal range Thought to be growth factor for many cancers Monitor thyroglobulin levels THYROID REPLACEMENT THERAPY
5% of thyroid cancers, 13.4% of thyroid cancer-related deaths Neuroendocrine tumor Arises from calcitonin-secreting parafollicular cells 75% are sporadic-presents as solitary nodule with palpable LAD MEDULLARY THYROID CANCER
Mets to lung, liver, bone frequent Neck, chest abdominal CT or MRI, calcitonin measurement done preoperatively 77% CEA, 27% serotonin Tx: total thyroidectomy + central neck dissection + ipsilateral modified radical neck dissection Post-op tx: Follow calcitonin No role for RAI MEDULLARY THYROID CANCER
More likely bilateral RET proto-oncogene-chromosome 10 (test before age 6) Prophylactic total thyroidectomy + central neck dissection after r/o pheochromocytoma Associated with C-cell hyperplasia MEDULLARY THYROID CANCER -HEREDITARY
Familial Medullary Carcinoma MEN-IIA MEN-IIB Least aggressive 4 or more MTCs in a family w/o associated endocrinopathy 2/3 of hereditary MTC Test for and treat pheochromocytoma first Most aggressive Earlier onset, genetic testing done early Total thyroidectomy + central neck dissection done before age 1 Test for and treat pheochromocytoma first MEDULLARY THYROID CANCER - HEREDITARY
Medullary Thyroid Cancer Primary Hyperparathyroidism Pheochromocytoma Cutaneous Lichen Amyloidosis Hirschsprung s disease 2-5% MEN-IIA
Medullary Thyroid Cancer Pheochromocytoma Mucosal Neuromas Marfanoid Habitus MEN II-B
1% of thyroid malignancies 1% of extranodal lymphomas Risk increased by Hashimoto s thyroiditis 75% large B cell, 25% MALT Tx: Chemo, radiation, total thyroidectomy if diagnosed intraoperatively PRIMARY THYROID LYMPHOMA
Renal cell, breast Tx: thyroidectomy when only site of mets METASTASES
Team approach: Reduces delays in treatment Reduces delays in referral to appropriate services Improves patients personal well being DEVELOPMENT OF A MULTIDISCIPLINARY TEAM FOR PEDIATRIC THYROID MALIGNANCY
Endocrinology Genetics Nuclear Medicine Oncology Pathology Pediatric Otolaryngology Pediatric Surgery Psychology Radiation Oncology OUR TEAM
Since initiation of our team in February 2016 Over 80 thyroidectomies have been performed Almost 200 local/national/international consulatations presented to our group Initiation of Genetic evaluation of our thyroid malignancy patients Increased participation with Psychological services to improve medication compliance Decreased travel for patients who need multiple services Improved outcomes Development of research to further care of pediatric patients with thyroid cancer/disorders OUR EXPERIENCE
Development of a protocol to identify and prevent low calcium following thyroid surgery Identification of patients who do not require hospitalization following thyroid surgery in the pediatric population Yielded confirmation that pediatric patients with PTC are more likely to require total thyroidectomy regardless of tumor size and BRAFV600 is more common in older patients Pediatric thyroid surgery outcomes Resulted in same day surgery for hemi-thyroidectomies and happier patients Exploration of characteristics in patients with genetic disorders who develop thyroid malignancy Le Bonheur, Boston Children s Le Bonheur/St. Jude, Lurie Children s, CHOP, Boston Children s AACE/AHNS Clinical Position Paper Le Bonheur/St. Jude, Lurie Children s, CHOP, Boston Children s,/harvard, Mayo Clinic, University of Florida, University of Arkansas RESULTING RESEARCH PROJECTS
QUESTIONS?