Approach to Thyroid Nodules Alice Y.Y. Cheng, MD, FRCPC Twitter: @AliceYYCheng
Copyright 2017 by Sea Courses Inc. All rights reserved. No part of this document may be reproduced, copied, stored, or transmitted in any form or by any means graphic, electronic, or mechanical, including photocopying, recording, or information storage and retrieval systems without prior written permission of Sea Courses Inc. except where permitted by law. Sea Courses is not responsible for any speaker or participant s statements, materials, acts or omissions.
Outline Thyroid basics Thyroid exam Approach to thyroid nodule Thyroid cancer Epidemiology Treatment
Thyroid Follicular cells: Make thyroid hormone (T4, T3) Parafollicular cells Make calcitonin Colloid = protein
What can go wrong? Functional Hyper / hypo Primary / Secondary Structural Nodules Both
Thyroid Exam
Two approaches Anterior Posterior
Thyroid exam Inspection anteriorly and laterally Landmark with your fingers Locate the isthmus Do NOT take your fingers off the patient The only things connected to the isthmus are the lobes!
Thyroid exam Comment on Size (# times normal) Texture (normal, firm, hard) Symmetry Nodular or smooth Mobility Tenderness
Approach to thyroid nodule
Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Miss. SF 17 year old woman Noted a lump in her neck Corresponds with a thyroid nodule on physical examination
Differential diagnosis Benign Colloid Hyperplastic Functional adenoma Cysts Malignant Papillary, follicular, medullary, anaplastic, lymphoma Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
What are key history features? Onset, rapidity of growth? Obstructive / compressive symptoms? Dyspnea, dysphagia, stridor Voice hoarseness Function? (hyper or hypo) Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Risk Factors for malignancy Age (< 20 or >65) Sex (M > F) Radiation history Cancer treatment, BMT Environmental (Chernobyl) Acne, tonsils Family history of thyroid cancer Rapid growth, hoarseness Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Risk Factors for malignancy Size (> 4 cm) Fixed Hard Lymphadenopathy Vocal cord paralysis Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Investigations TSH (functional?) Functional nodules are BENIGN
Question A thyroid scan should be part of the routine work up of thyroid nodules to differentiate between benign or malignant. TRUE FALSE
Nuclear Medicine tests NOT necessary in most cases! Uptake: Test of FUNCTION and not structure Useful if HYPERTHYROID Scan: Test of STRUCTURE and not function Useful if HYPERTHYROID and NODULE Only useful finding = hot
Ultrasound Investigations True nodule? Cyst? Size? Composition, echogenicity Margins Calcifications (type) Shape Vascularity Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Ultrasound predictors of cancer Sensitivity (%) Specificity (%) Microcalcifications 44 89 Hypoechoic 81 53 Solid 86 18 Absence of halo 66 54 Intranodular vascularity 62 77 Poorly defined margins 55 79 Tall>Wide 48 92 Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Risk stratification by U/S HIGH MEDIUM LOW VERY LOW BENIGN Hypoechoic with irregular margins Microcalcifications Taller > wide Interrupted rim calcification Suspicious lymph node Hypoechoic solid nodule with regular margins Hyperechoic or isoechoic solid nodule with regular margins Partly cystic with eccentric solid component Spongiform Cystic with benign-looking solid component Simple cyst Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Fine needle aspiration biopsy FNA is the procedure of choice in the evaluation of thyroid nodules (Recommendation A) Ultrasound guided or palpation Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
U/S Patterns and FNA Suggestions U/S Patterncancer risk Est cancer risk Threshold for FNA Strength High 70-90% 1 cm Strong Intermediate 10-20% 1 cm Strong Low 5-10% 1.5 cm Weak Very Low <3% 2 cm Weak Benign <1% No FNA Strong Do NOT biopsy any nodule < 1 cm Strong Modify cutoffs based on risk factors, suspicious lymph nodes Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
Multiple nodules and FNA When multiple nodules > 1 cm are present, FNA based on US pattern If multiple similar low or very low risk nodules are present, it is reasonable to FNA the largest ( over 2 cm) and observe the others Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
FNAB results 1. Malignant = surgery 2. Benign = follow 3. Indeterminate = surgery 4. Inadequate = repeat FNAB
Non-diagnostic cytology Repeat US guided FNAB Repeatedly non-diagnostic cytology WITHOUT suspicious U/S pattern OBSERVE closely or excised WITH suspicious U/S pattern, growth, or clinical risk factors SURGERY Haugen BR et al. 2015 ATA Guidelines. Thyroid 2015;DOI:10.1089/thyr.2015.0020
F/U of benign cytology US- guided FNA has a very low false negative rate US pattern High suspicion Repeat US and FNA in 12 mo Medium/low suspicion Very low suspicion Repeat US 12-24 mo, if growth* repeat FNA or observe Utility unknown- if repeated, wait >24 mo If a second FNA is benign, US surveillance is NOT indicated Strength Strong Weak None Strong * Growth defined as 50% increase in volume, or 20% increase in dimensions
F/U if NOT initially biopsied US pattern Strength High suspicion Repeat US in 6-12 mo Weak Medium/low suspicion Very low suspicion Repeat US 12-24 mo Utility unknown- if repeated, wait >24 mo Nodules < 5 mm do not require routine US followup Weak No rec Week
Miss. SF 17 year old woman Noted a lump in her neck Corresponds with a thyroid nodule on physical examination WHAT WOULD YOU DO?
Take home points Risk factors for malignancy radiation, family history, age, sex, Phillipino Size (>4cm), obstruction/compression Ultrasound features U/S, TSH, FNAB for almost all Uptake & scan ONLY if hyperthyroid Only investigate > 1-2 cm based on risk
Thyroid Cancer
Cancer Care Ontario: Cancer in Young Adults in Canada, May 2006
Thyroid Cancer Differentiated (90%) Papillary Follicular Medullary Anaplastic Lymphoma
Usual Treatment Total thyroidectomy vs lobectomy Radioiodine remnant ablation in some I131 inpatient or outpatient Low iodine diet 2 weeks prior Must have TSH > 35 Withdrawal or Thyrogen Whole body scan 1 week later Allows for surveillance with thyroglobulin
Treatment Suppressive thyroid replacement TSH < 0.1 in high risk cases TSH 0.1-0.5 other cases
Thyroglobulin Surveillance Check at 6-12 months after ablation Stimulated Tg is the best test Withdrawal or Thyrogen Must have NEGATIVE antibody levels I131 whole body scan (not always) Other imaging (U/S, CT, PET)
Surveillance Surveillance must be life long! Monitor Clinical exam Ultrasounds Thyroglobulin on suppression Periodic stimulated thyroglobulins
Take home points Thyroid cancer is common and growing Prognosis excellent but recurrence rate is high lifelong surveillance Thyroidectomy, suppression, remnant ablation, surveillance with Tg