Thyroid Cancer — TNM

Name: Thyroid Cancer — TNM calculator — MedScore
Creator: Nabil Alzein

AJCC 8th edition (2017) — differentiated (papillary and follicular) thyroid carcinoma; age at diagnosis is part of the stage

Age at diagnosis

Under 55 years

55 years or older

T — primary tumour

T1 — ≤ 2 cm, limited to the thyroid

T2 — > 2 cm and ≤ 4 cm, limited to the thyroid

T3a — > 4 cm, limited to the thyroid

T3b — gross extrathyroidal extension invading only the strap muscles (any size)

T4a — gross extension into subcutaneous soft tissue, larynx, trachea, oesophagus or recurrent laryngeal nerve

T4b — gross extension into prevertebral fascia, or encasing the carotid artery or mediastinal vessels

N — regional lymph nodes

N0 — no evidence of locoregional lymph node metastasis

NX — regional lymph nodes cannot be assessed

N1 — metastasis to regional nodes

M — distant metastasis

M0 — no distant metastasis

M1 — distant metastasis

About this score

When to use

Assigns the AJCC 8th-edition stage of differentiated (papillary and follicular) thyroid carcinoma, with the age cut-off at 55 years. ⁦[1]⁩

Pearls and pitfalls

Medullary and anaplastic thyroid carcinoma use different tables and are not covered here. ⁦[2]⁩

Summarised from the numbered sources under Evidence. Check the source before relying on a statement.

Evidence

[1] Original publication

Amin MB, Edge SB, Greene FL, et al., eds. AJCC Cancer Staging Manual, 8th edition. New York: Springer; 2017. Differentiated (papillary and follicular) thyroid carcinoma, with the age cut-off at 55 years. Confirm against the manual.

Springer, 2017

[2] Guideline

PDQ® Adult Treatment Editorial Board. Thyroid Cancer Treatment (PDQ®) – Health Professional Version. National Cancer Institute — reprints the AJCC 8th-edition stage tables. Medullary and anaplastic carcinoma use different tables and are not covered here.

Open source

Last reviewed: 2026-10

Report an error in this calculator

MedScore is an educational and clinical decision-support tool. It does not provide a diagnosis, a treatment, or a drug-dosing recommendation, and it does not replace clinical judgement or local guidelines. Confirm every result against the original source before acting on it. The treating clinician remains responsible for all decisions.