Approach to Thyroid Nodule[1]

(1)

APPROACH

TO

THYROID NODULE

Dr. (Maj. Gen.) K J Shetty

Consultant Endocrinologist

MD, FRCP (Edin.), FICP

(2)

(3)

(4)

(5)

(6)

INTRODUCTION

Thyroid Nodule:

– Common Outpatient Clinical Problem_{Common Outpatient Clinical Problem}

4 to 8% OF ADULTS 4 to 8% OF ADULTS 13 to 67% ON USG EXAM 13 to 67% ON USG EXAM (Female : Male – 8:1) (Female : Male – 8:1)

– Importance: Concern of Carcinoma_{Importance: Concern of Carcinoma}

5% Malignant

Relative Common-ness and possibility of complete cure if

detected early

– Solution:_Solution: Evolve a safe, expedient, reliable and cost Evolve a safe, expedient, reliable and cost

(7)

PRESENT SCENARIO

Widely Divergent Approach

– Primary Consultant : GP, Internist, Surgeon, _{Primary Consultant : GP, Internist, Surgeon,}

ENT Specialist, Surgical OncologistENT Specialist, Surgical Oncologist

– Bias of the consultant - reluctance to follow guidelines_{Bias of the consultant - reluctance to follow guidelines} – Inadequate use/ Improper prioritization of _{Inadequate use/ Improper prioritization of}

investigative tools investigative tools

– Insufficient knowledge of pathophysiology _{Insufficient knowledge of pathophysiology}

natural history of thyroid nodule

indications, merits, and shortcomings of various investigative

tools

(8)

Approach to Thyroid Nodule

Steps:

Evaluation

– Morphology_Morphology – Functional_Functional – Immunological_{Immunological} – Cytological_Cytological – Histopathological_{Histopathological}

Tools Available

– Clinical History & Examination_{Clinical History & Examination}

– Biochemical / Immunological Tests_{Biochemical / Immunological Tests} – Imaging – USG/SCAN_{Imaging – USG/SCAN}

(9)

Thyroid Nodule

Steps in Evaluation:

–

_{Clinical Examination}

–

Biochemical Examination

_{Biochemical Examination}

–

Ultrasound Evaluation

_{Ultrasound Evaluation}

(10)

Clinical Evaluation

Asymptomatic

Symptomatic

Hyper/ Hypo-thyroidism

Mechanical

Dyspnoea Dyspnoea Dysphagia Dysphagia Hoarseness Hoarseness Pain Pain

Rapid Increase In Size

Cosmetic

Past History (Previous Surgery, Irradiation)

Family History

(11)

CLINICAL EVALUATION (cont’d)

General

– Sex: M > F_{Sex: M > F}

– _{Age: < 20 ; > 60 Yrs}_{Age: < 20 ; > 60 Yrs}

Systemic

: EUTHYROID/ HYPO/ HYPER

Neck

: NODULE: SOLITARY / MULTINODULAR

– Size/ Intra-thoracic/ Extension_{Size/ Intra-thoracic/ Extension} – Consistency: Firm/Hard/Cystic_{Consistency: Firm/Hard/Cystic} – Mobile/Fixed_Mobile/Fixed

– Tenderness_Tenderness

Lymph nodes

(12)

CLINICAL POINTERS TO MALIGNANCY

Main Pointers

– Recent Rapid Increase In Size_{Recent Rapid Increase In Size}

– Development of Hoarseness of voice_{Development of Hoarseness of voice} – Positive Family History_{Positive Family History}

– Age & Sex_{Age & Sex}

– Past History of Neck Irradiation_{Past History of Neck Irradiation} – Hard Fixed Nodule_{Hard Fixed Nodule}

– Regional lymph nodes_{Regional lymph nodes}

Misconcepts of Malignancy

– Size: Smaller Ones – NO RISK_{Size: Smaller Ones – NO RISK} – Multi-Nodular – NO RISK_{Multi-Nodular – NO RISK}

(13)

Biochemical Evaluation

– Lab Evaluation_{Lab Evaluation} – First Step: Assess Functional Status – First Step: Assess Functional Status

by TFTby TFT

– TSH Assay_{TSH Assay}: Most Useful : Most Useful

– T3/T4_T3/T4: Not Necessary if TSH is normal: Not Necessary if TSH is normal

– TSH:_TSH:

Absent/ Low - Toxic Nodule : T3/ T4 Indicated

Elevated - Hypothyroid : T4 indicated

– FT3/FT4_FT3/FT4: Preferred to TT3/ TT4: Preferred to TT3/ TT4

– Thyroid Antibodies_{Thyroid Antibodies}

Thyroid Peroxidase (TPO)

ANTI-THYROGLOBULIN Ab (TgAb)

TSH Receptor

Antibodies (TSIAb) Graves (Not Routinely Available)

(14)

Ultrasonography (USG)

*

High Resolution USG: Exceptional Clarity

*Nodules < 1.5 cm *Nodules < 1.5 cm

*Metastatic Nodules In Neck (Clinically not palpable) *Metastatic Nodules In Neck (Clinically not palpable)

• Assists in Localising Nodules for FNAC

_{Assists in Localising Nodules for FNAC}

• Inexpensive, non invasive, readily available

_{Inexpensive, non invasive, readily available}

• USG to Endocrinologist

_{USG to Endocrinologist}

Stethoscope to Cardiologist

• _Limitation

_Limitation

_{: Little help in differentiating benign}

(15)

No Single Characteristic: Predictive for malignancy No Single Characteristic: Predictive for malignancy

Denote Higher Risk in combination of some: Denote Higher Risk in combination of some:

Composition

Composition Incidence percentage Incidence percentage – Solid_Solid 27%27%

– Mixed (complex)_{Mixed (complex)} 7% 7%

– Pure cystic_{Pure cystic} > 4 cm: 6% > 4 cm: 6%

< 4 cm: Negligible < 4 cm: Negligible

Calcification Calcification

– Microcalcification : x 3 higher risk without calcification_{Microcalcification : x 3 higher risk without calcification} – 95% specificity_{95% specificity}

- Coarse Calcification x 2 Risk- Coarse Calcification x 2 Risk

Cervical Lymph Nodes : Highly Suggestive of PTC Cervical Lymph Nodes : Highly Suggestive of PTC

(16)

Fine Needle Aspiration Cytology (FNAC) /

Biopsy (FNAB)

Crucial Step in evaluation Crucial Step in evaluation

Simple, safe, accurate and cost effective Simple, safe, accurate and cost effective

Assess Reliability Guidelines (Mayo Clinic) Assess Reliability Guidelines (Mayo Clinic)

– Experienced, Preferably dedicated cyto-pathologist_{Experienced, Preferably dedicated cyto-pathologist} – Multiple Sites of Aspiration (2-4)_{Multiple Sites of Aspiration (2-4)}

– A Low False Negative Rate_{A Low False Negative Rate}

Literature 1 – 11 %

Acceptable < 5%

Diagnostic Sample : 2 Slides - > 6 Groups Each

> 10 Follicular Cells In each > 10 Follicular Cells In each group group Benign………. 70% Benign………. 70% Indeterminate………..10% Indeterminate………..10% Malignant……… 5% Malignant……… 5% Non Diagnostic………15% Non Diagnostic………15%

(17)

Benign: Colloid Nodules

–

70% Simple Cysts

_{70% Simple Cysts}

–

AutoImmune/ Lymphocytic Thyroiditis

_{AutoImmune/ Lymphocytic Thyroiditis}

Malignant:

–

_{Papillary (Commonest) 83%}

–

Follicular : 11%

_{Follicular : 11%}

–

Medullary (MTC) 5%

_{Medullary (MTC) 5%}

–

Anaplastic

_Anaplastic

1%

(18)

Indeterminate Category: (10%)

2 GROUPS:

–

_{Suspicious for malignancy: definitive evidence}

for malignancy not evident

–

Follicular neoplasm: not possible to

_{Follicular neoplasm: not possible to}

differentiate from adenoma and carcinoma

(capsular/ lymphovascular invasion)

Both sub-groups qualify for surgery

(19)

Non-Diagnostic (20%)

Solid Lesion

- Insufficient No. of follicular Cells- Insufficient No. of follicular Cells

- Re-Aspiration Indicated after 4 weeks- Re-Aspiration Indicated after 4 weeks

– diagnostic aspirate in 50%diagnostic aspirate in 50%

– if non diagnostic : surgeryif non diagnostic : surgery

Cystic Lesion

- Aspirate Unsatisfactory- Aspirate Unsatisfactory

- Solid Component- Biopsy Mandatory- Solid Component- Biopsy Mandatory

(20)

THYROID SCINTIGRAPHY

Using Radioactive Iodine (I

Using Radioactive Iodine (I131131) / Technitium (99 mTc)_{) / Technitium (99 mTc)}

Depending on uptake classified as:

– HOT_HOT: 5% Toxic Nodule : < 5% Malignant: 5% Toxic Nodule : < 5% Malignant

– COLD_COLD: 80 – 85% : 10 – 15% Malignant: 80 – 85% : 10 – 15% Malignant

– WARM_WARM 10-15% : 9% Malignant 10-15% : 9% Malignant

– Expensive/ Availability Only In Special Centres_{Expensive/ Availability Only In Special Centres} – Overlap: Small Nodules Masked_{Overlap: Small Nodules Masked}

Use Limited To

Use Limited To : :

– Indeterminate (Suspicious/Follicular) on FNAC_{Indeterminate (Suspicious/Follicular) on FNAC} – Follow Up of “hot” nodule_{Follow Up of “hot” nodule}

(21)

NORMAL Tc99m THYROID UPTAKE

(22)

HOT NODULE

(23)

COLD NODULE

(24)

MULTI-NODULAR GOITRE

(25)

MANAGEMENT

Based on Combination of Input From:

– History_History

– Clinical Examination_{Clinical Examination} – Ultrasound Evaluation_{Ultrasound Evaluation} – Cytology_Cytology

( Benign Nodules, Malignant Nodules, Indeterminate, Nondiagnostic)

Therapeutic Options:

1.

1. Follow-Up With Periodic Clinical and lab inputFollow-Up With Periodic Clinical and lab input 2.

2. SurgerySurgery 3.

3. RadiotherapyRadiotherapy 4.

(26)

MANAGEMENT (contd….)

BENIGN NODULES (70%):

– Euthyroid: No Pressure symptoms Yearly Follow up_{Euthyroid: No Pressure symptoms Yearly Follow up}

Cosmetically Acceptable Clinical/Biochem./ USGCosmetically Acceptable Clinical/Biochem./ USG

> 20% > 20% ↑ - Repeat FNAC↑ - Repeat FNAC

– Role of Suppressive Rx with T4 – Not Proven_{Role of Suppressive Rx with T4 – Not Proven} – Beware of subclinical Hyperthyroidism_{Beware of subclinical Hyperthyroidism}

– Euthyroid: Pressure + Cosmetic Problem – Limited Surgery_{Euthyroid: Pressure + Cosmetic Problem – Limited Surgery} – Toxic Nodule: Medical (CMZ/PTU _{Toxic Nodule: Medical (CMZ/PTU}++ Propranolol) Propranolol)

(27)

MANAGEMENT (cont…)

Malignant Nodules: 5%

PTC

PTC : Total Thyroidectomy with Ipsilateral Central : Total Thyroidectomy with Ipsilateral Central

Compartment Lymph Node ClearanceCompartment Lymph Node Clearance FTC

FTC: Non/Min. Invasive – Lobectomy: Non/Min. Invasive – Lobectomy

Invasive: Complete Thyroidectomy (Total)Invasive: Complete Thyroidectomy (Total) Follow Up for Both

Follow Up for Both : I : I131131 ablation after 6/52_{ablation after 6/52}

High Dose Thyroxine High Dose Thyroxine

TSH Suppression (<0.1mu/L)TSH Suppression (<0.1mu/L) MTC

MTC: Total Thyroidectomy with complete LN Clearance: Total Thyroidectomy with complete LN Clearance ANAPLASTIC

(28)

MANAGEMENT (cont…)

INDETERMINATE (10%)

FOLLICULAR NEOPLASM / SUSPICIOUS FOR MALIGNANCY

SURGERY WITH INTRAOPERATIVE FROZEN SECTION

TOTAL THYROIDECTOMY

+

(29)

MANAGEMENT (cont…)

NON DIAGNOSTIC : 20%

CYSTS : > 4 cm

– REPEATED FNAC

– NONDIAGNOSTIC/ SURGERY

NODULE –

(30)

APPROACH TO THYROID NODULE – AN ALGORITHM

USG

CLINICAL EVALUATION +

TFT + IMMUNOLOGY

SOLID COMPLEX CYSTS WITH

SOILD COMPUND

PURE CYSTS

< 4cm > 4 cm

PATIENT WITH THYROID NODULE

EUTHYROID HYPERTHYROID HYPOTHYROID

ANTITHYROID DRUGS/ I 131 _{ABLATION / SURGERY}

(31)

FNAC OF NODULE

CYTOLOGY REPORT

BENIGN (70%) _{MALIGNANT (5%)} _{INDETERMINATE (10%)} NON DIAGNOSTIC (15%)

PRESSURE SYMPTOMS/ COSMETIC PROBLEMS – NIL YEARLY

FOLLOWUP

SCINTIGRAPHY

(I131_{/ 99 mTc)} Rpt FNAC WITH USG

Rpt FNAC SUSPICIOUS

WARM COLD DIAGNOSTIC

SURGERY FOLLOWUP > 20% INCREASE SUPPRESSION WITH T4 – 6– 12 MONTHS NON-DIAGNOSTIC