Thyroid nodule classification

Jump to: navigation, search

Thyroid nodule Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Thyroid nodule from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic study of choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Thyroid nodule classification On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Thyroid nodule classification

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Thyroid nodule classification

CDC on Thyroid nodule classification

Thyroid nodule classification in the news

Blogs on Thyroid nodule classification

Directions to Hospitals Treating Thyroid nodule

Risk calculators and risk factors for Thyroid nodule classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mahshid Mir, M.D. [2]

Overview

There are various methods for classifying a thyroid nodule. A method has been developed by the National Cancer Institute (NCI) to address terminology and other issues related to thyroid fine-needle aspiration (FNA), called "The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC)". The other classification method is the TNM classification (tumor-node-metastasis) method developed by the American Joint Committee on Cancer and the International Union against Cancer focused on prognosis has been established to avoid heterogeneity of prognostic classification schemes used for differentiated thyroid cancers. Thyroid nodules may also be classified based on their ultrasound properties according to the TIRAD classification method, which has been proposed by Horvath et al, with a modified recommendation from Jin Kwak et al, and finally, thyroid nodules may also be classified on the basis of origin.

Classification

 
 
 
 
 
 
 
Thyroid nodule classification
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Bethesda classification system
 
 
 
 
 
 
 
 
 
 
TIRAD classification system
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Based on thyroid cytopathology
 
 
 
 
 
 
 
 
 
 
Based on sonographic features
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Benign
•Nondiagnostic or Unsatisfactory
•Follicular lesion of undetermined significance
Atypia of undetermined significance
•Follicular neoplasm
•Suspicious for a follicular neoplasm
Malignant
 
 
 
 
 
 
 
 
 
 
•TIRADS 1=Normal thyroid gland
•TIRADS 2=Benign lesions
•TIRADS 3=Probably benign lesions
•TIRADS 4= Contain 1-4 suspicious features
•TIRADS 5=Contain all five suspicious features
•TIRADS 6=Biopsy proven malignancy
 
 
 
 
 
 
 
Differentiated and anaplastic thyroid carcinoma
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TNM staging AJCC UICC 2017
 
 
 
 
 
Classification based on their origin
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
•Primary tumor (T)
•Regional lymph nodes (N)
•Distant metastasis (M)
 
 
Nonmedullary (epithelial) thyroid cancers (NMTCs)
•Papillary cell tumors
•Follicular tumors
•Hurthle cell tumors
•Anaplastic tumors
 
 
 
Medullary thyroid cancers
 
 

The Bethesda System For Reporting Thyroid Cytopathology

To address terminology and other issues related to thyroid fine-needle aspiration (FNA), the National Cancer Institute (NCI) developed a new classification method called "The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC)".[1]

Classification FNA cytology Predicted risk of malignancy
Benign 0–3 %
Nondiagnostic or unsatisfactory --- 1–4 %
Follicular lesion of undetermined significance
  • Mixed macro- and microfollicular nodules
5–15 %
Atypia of undetermined significance
Follicular neoplasm 15–30 %
Suspicious for a follicular neoplasm 60–75 %
Malignant 97–99 %

Abbreviations: PTC- Papillary thyroid carcinoma, MTC- Medullary thyroid carcinoma

Classification Based On TNM Staging

The TNM classification (tumor-node-metastasis) was adopted by the American Joint Committee on Cancer and the International Union against Cancer more than 10 years ago. This classification system mainly focuses on prognosis and is developed to avoid heterogeneity of prognostic classification schemes used for differentiated thyroid cancers.[2]

Differentiated and anaplastic thyroid carcinoma TNM staging AJCC UICC 2017

Papillary, follicular, poorly differentiated, Hurthle cell and anaplastic thyroid carcinoma
Primary tumor (T) Regional lymph nodes (N) Distant metastasis (M)
T category T criteria N category N criteria M category M criteria
TX Primary tumor cannot be assessed NX Regional lymph nodes cannot be assessed M0 No distant metastasis
T0 No evidence of primary tumor N0 No evidence of locoregional lymph node metastasis M1 Distant metastasis
T1 Tumor ≤2 cm in greatest dimension limited to the thyroid N0a One or more cytologically or histologically confirmed benign lymph nodes
T1a Tumor ≤1 cm in greatest dimension limited to the thyroid N0b No radiological or clinical evidence of local regional lymph node metastases
T1b Tumor >1 cm but ≤2 cm in greatest dimension limited to the thyroid N1 Metastasis to regional nodes
T2 Tumor >2 cm but ≤4 cm in greatest dimension limited to the thyroid N1a Metastases to level VI or VII (pretracheal, paratracheal, or prelaryngeal/Delphian, or upper mediastinal) lymph nodes. This can be unilateral or bilateral disease
T3 Tumor >4 cm limited to the thyroid, or gross extrathyroidal extension invading only strap muscles N1b Metastasis to unilateral, bilateral, or contralateral neck lymph nodes (levels I, II, III, IV, or V) or retropharyngeal lymph nodes
T3a Tumor >4 cm limited to the thyroid
T3b Gross extrathyroidal extension invading only strap muscles (sternohyoid, sternothyroid, thyrohyoid, or omohyoid muscles) from a tumor of any size
T4 Includes gross extrathyroidal extension
T4a Gross extrathyroidal extension invading subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve from a tumor of any size
T4b Gross extrathyroidal extension invading prevertebral fascia or encasing the carotid artery or mediastinal vessels from a tumor of any size

Thyroid Nodule Classification Based On Ultrasound Features

A classification system has been proposed by Horvath et al, with a modified recommendation from Jin Kwak et al.[3]

Ultrasound classification Features Risk of Malignancy
TIRADS 1 Normal thyroid gland
TIRADS 2 Benign lesions
  • Avascular anechoic lesion with echogenic specks (colloid type I)
  • Vascular heteroechoic non-expansile, non-encapsulated nodules with peripheral halo (colloid type II)
  • Isoechoic or heteroechoic, non-encapsulated, expansile vascular nodules (colloid type III)
0% risk of malignancy
TIRADS 3 Probably benign lesions <5% risk of malignancy
TIRADS 4 4a One suspicious feature
  • Suspicious lesions:
    • Solid component
    • High stiffness of nodule on elastography if available
    • Markedly hypoechoic nodule
    • Microlobulations or irregular margins
    • Microcalcifications
    • Taller-than-wider shape
5-10% risk of malignancy
4b Two suspicious features 10-80% risk of malignancy
4c Three/four suspicious features
TIRADS 5 All five suspicious features Probably malignant lesions (more than 80% risk of malignancy) >80% risk of malignancy
TIRADS 6 Biopsy proven malignancy

Classification Of Neoplastic Thyroid Nodules Based On Their Origin:

Origin Prevalence Origin Histologic Classification Subclass
Nonmedullary thyroid cancers (NMTCs) 95% of tumors Thyroid epithelial cells Papillary (85%)
  • Classic variant
  • Tall cell variant
  • Insular variant
  • Columnar variant
  • Hürthle or oxyphilic variant
  • Solid or trabecular variant
  • Clear cell variant
  • Diffuse sclerosing variant
  • Cribriform-morular variant
  • Hobnail variant
Follicular (11%)
Hürthle cell (3%)
Anaplastic (1%)
Medullary thyroid cancers (MTCs) 5% of all thyroid malignancies Calcitonin-producing parafollicular cells

References

  1. Cibas ES, Ali SZ (2009). "The Bethesda System for Reporting Thyroid Cytopathology". Thyroid. 19 (11): 1159–65. doi:10.1089/thy.2009.0274. PMID 19888858.
  2. Loh KC, Greenspan FS, Gee L, Miller TR, Yeo PP (1997). "Pathological tumor-node-metastasis (pTNM) staging for papillary and follicular thyroid carcinomas: a retrospective analysis of 700 patients". J. Clin. Endocrinol. Metab. 82 (11): 3553–62. doi:10.1210/jcem.82.11.4373. PMID 9360506.
  3. Horvath E, Majlis S, Rossi R, Franco C, Niedmann JP, Castro A, Dominguez M (2009). "An ultrasonogram reporting system for thyroid nodules stratifying cancer risk for clinical management". J. Clin. Endocrinol. Metab. 94 (5): 1748–51. doi:10.1210/jc.2008-1724. PMID 19276237.

Linked-in.jpg