Thyroid gland
TNM staging of carcinomas

Author: Shahidul Islam, M.D., Ph.D. (see Authors page)

Revised: 22 February 2017, last major update March 2009

Copyright: (c) 2003-2017,, Inc.

PubMed Search: TNM staging thyroid carcinoma

Cite this page: TNM staging of carcinomas. website. Accessed November 19th, 2017.
Clinical Staging
  • Based on inspection / palpation of thyroid gland and regional lymph nodes
  • Indirect laryngoscopy is performed to evaluate vocal cord motion
  • Other imaging procedures without iodine contrast may be useful (iodine contrast delays use of I-131 for treatment)
  • Preoperative ultrasound recommended for papillary thyroid carcinoma (Arch Otolaryngol Head Neck Surg 2007;133:1258)
Pathologic Staging
Primary Tumor (T)
  • Categories may be subdivided as solitary tumor (s) or multifocal tumor (m); the largest determines the classification

  • TX: Primary tumor cannot be assessed
  • T0: No evidence of primary tumor
  • T1: Limited to thyroid, 2 cm or less in greatest dimension
  • T1a: Limited to thyroid, 1 cm or less
  • T1b: Limited to thyroid, more than 1 cm but not more than 2 cm
  • T2: Limited to thyroid, greater than 2 cm, but not more than 4 cm
  • T3: Limited to thyroid and > 4 cm OR any tumor with minimal extrathyroid extension (e.g., extension to sternothyroid muscle or perithyroid soft tissues)
  • T4a: Moderately advanced disease
    • Tumor of any size extending beyond the thyroid capsule to invade subcutaneous soft tissues, larynx, trachea, esophagus or recurrent laryngeal nerve
  • T4b: Very advanced disease
    • Tumor invades prevertebral fascia or encases carotid artery or mediastinal vessels

Anaplastic carcinoma - all are considered T4 tumors
  • T4a: Intrathyroidal anaplastic carcinoma
  • T4b: Anaplastic carcinoma with gross extrathyroid extension
Regional Lymph Nodes (N)
  • NX: Regional lymph nodes cannot be assessed
  • N0: No regional lymph node metastasis
  • N1: Regional lymph node metastasis
  • N1a: Metastasis to Level VI (pretracheal, paratracheal and prelaryngeal / Delphian lymph nodes)
  • N1b: Metastasis to unilateral, bilateral or contralateral cervical (Levels I, II, III, IV or V) or retropharyngeal or superior mediastinal lymph nodes (Level VII)

  • Selective neck dissection usually includes 6+ lymph nodes
  • Radical or modified radical neck dissection includes 10+ lymph nodes
  • Regional lymph nodes are the central compartment, lateral cervical and upper mediastinal lymph nodes
Diagrams / tables

Images hosted on other servers:

Cervical lymph node levels

Clinical images

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Central compartment

Distant Metastasis (M)
  • M0: No distant metastasis
  • M1: Distant metastasis
Stage Grouping
  • Note: stage groups are based on histologic type and age

Papillary or follicular:
Under 45 years 45 years or older
Stage I any T   any N   M0     T1 N0 M0
Stage II any T any N M1 T2 N0 M0
Stage III T3 N0 M0
T1 - 3 N1a M0
Stage IVA T4a N0 - 1a M0
T1 - 4a N1b M0
Stage IVB T4b any N M0
Stage IVC     Any T   any N   M1

Medullary carcinoma:
Stage I T1 N0 M0
Stage II T2 - 3 N0 M0
Stage III T1 - 3 N1a M0
Stage IVA T4a N0 - 1a M0
T1 - 4a N1b M0
Stage IVB T4b any N M0
Stage IVC     Any T   any N   M1

Anaplastic carcinoma (all cases are Stage IV):
Stage IVA     T4a any N M0
Stage IVB T4b any N M0
Stage IVC Any T   any N   M1
Additional references