Tnm classification of head and neck ca Construct a tabular form where its easy to differentiate and fast to learn
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"head and neck neoplasms" AND TNM
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AJCC 8th edition head and neck cancer TNM oral cavity larynx oropharynx staging definitions
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https://pmc.ncbi.nlm.nih.gov/articles/PMC6528815
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TNM classification of head and neck cancer: fast-learning table
Important: There is no single T classification for every head and neck primary. T is site-specific, while the following cN table is shared by most mucosal squamous-cell carcinomas: oral cavity, p16-negative oropharynx, hypopharynx, and larynx.
1. Basic meaning
| Component | Meaning | Fast recall |
|---|---|---|
| T | Primary tumor size and local invasion | Site-specific |
| N | Regional cervical lymph nodes | Size + side + number + ENE |
| M | Distant metastasis | M0 absent, M1 present |
| ENE | Extranodal extension, tumor extending beyond lymph-node capsule | ENE+ = bad prognosis |
2. Common clinical N classification: most mucosal head and neck SCC
Applicable to: oral cavity, p16-negative oropharynx, hypopharynx, larynx.
| N stage | Lymph-node finding | Memory cue |
|---|---|---|
| N0 | No regional lymph-node metastasis | 0 nodes |
| N1 | Single ipsilateral node, ≤3 cm, ENE negative | One, same side, ≤3 |
| N2a | Single ipsilateral node >3 cm but ≤6 cm, ENE negative | One 3-6 |
| N2b | Multiple ipsilateral nodes, none >6 cm, ENE negative | Many, same side |
| N2c | Bilateral or contralateral nodes, none >6 cm, ENE negative | Crosses midline |
| N3a | Node >6 cm, ENE negative | >6 |
| N3b | Any node(s) with clinically overt ENE positive | ENE = N3b |
N-stage mnemonic
| N group | Key idea |
|---|---|
| N1 | One same-side node, ≤3 cm |
| N2a | One same-side node, 3-6 cm |
| N2b | Multiple same-side nodes |
| N2c | Contralateral or bilateral nodes |
| N3a | >6 cm |
| N3b | ENE positive |
ENE is the key AJCC 8 update for the usual mucosal head and neck cancers: clinically overt ENE upgrades nodal status to cN3b. It is not used in the same way for HPV-mediated p16-positive oropharyngeal carcinoma and nasopharyngeal carcinoma. AJCC 8 review
3. Oral cavity cancer: most important exam table
Includes tongue anterior two-thirds, buccal mucosa, floor of mouth, gingiva, hard palate, retromolar trigone, and mucosal lip.
Key addition: DOI = depth of invasion, not tumor thickness.
| T stage | Tumor criteria | Fast recall |
|---|---|---|
| Tis | Carcinoma in situ | In situ |
| T1 | ≤2 cm and DOI ≤5 mm | 2 cm / 5 mm |
| T2 | ≤2 cm with DOI >5 to ≤10 mm OR >2 to ≤4 cm with DOI ≤10 mm | 2-4 cm or 5-10 mm DOI |
| T3 | >4 cm OR DOI >10 mm | >4 cm or >10 mm DOI |
| T4a | Invades cortical bone of mandible/maxilla, maxillary sinus, or skin of face | Bone / sinus / skin |
| T4b | Invades masticator space, pterygoid plates, skull base, or encases internal carotid artery | Masticator / skull base / carotid |
Oral cavity mnemonic
“2-4-10, then BSC”
- 2 cm with DOI 5 mm = T1
- 2-4 cm or DOI 5-10 mm = T2
- >4 cm or DOI >10 mm = T3
- BSC = Bone, Sinus, Cutaneous skin invasion = T4a
- Masticator space, skull base, carotid encasement = T4b
Superficial erosion of the tooth socket alone in a gingival primary does not automatically make the lesion T4a. Scott-Brown's Otorhinolaryngology Head & Neck Surgery, p. 84.
4. Oropharynx: p16-negative cancer
| T stage | Criteria | Fast recall |
|---|---|---|
| T1 | ≤2 cm | ≤2 |
| T2 | >2 cm to ≤4 cm | 2-4 |
| T3 | >4 cm or extension to lingual surface of epiglottis | >4 / epiglottis |
| T4a | Invades larynx, extrinsic tongue muscles, medial pterygoid, hard palate, or mandible | Local deep invasion |
| T4b | Invades lateral pterygoid, pterygoid plates, lateral nasopharynx, skull base, or encases carotid | Skull base / carotid |
5. HPV-mediated oropharyngeal carcinoma: p16-positive
| T stage | Criteria |
|---|---|
| T0 | No primary identified but p16-positive cervical node metastasis |
| T1 | ≤2 cm |
| T2 | >2 cm to ≤4 cm |
| T3 | >4 cm or extension to lingual epiglottis |
| T4 | Invades larynx, extrinsic tongue muscle, medial pterygoid, hard palate, mandible, or beyond |
HPV-positive oropharynx: clinical N stage
| N stage | Criteria |
|---|---|
| N0 | No regional nodes |
| N1 | One or more ipsilateral nodes, all ≤6 cm |
| N2 | Contralateral or bilateral nodes, all ≤6 cm |
| N3 | Any node >6 cm |
Do not use the usual N2a/N2b/N2c/N3b pattern for p16-positive oropharyngeal cancer.
6. Hypopharynx
| T stage | Criteria | Fast recall |
|---|---|---|
| T1 | ≤2 cm and confined to one subsite | Small, one subsite |
| T2 | >2 to ≤4 cm, or invades adjacent hypopharyngeal subsite/site | 2-4 or adjacent |
| T3 | >4 cm, fixed hemilarynx, or esophageal mucosal extension | >4 / fixation |
| T4a | Invades thyroid/cricoid cartilage, hyoid bone, thyroid gland, esophageal muscle, or central compartment soft tissue | Cartilage / thyroid |
| T4b | Prevertebral fascia, carotid encasement, or mediastinal involvement | Prevertebral / carotid / mediastinum |
7. Larynx: rapid high-yield differentiation
A. Supraglottis
| T stage | Main point |
|---|---|
| T1 | Limited to one supraglottic subsite; vocal cords mobile |
| T2 | Invades more than one adjacent supraglottic or glottic subsite, or adjacent region outside larynx; cords not fixed |
| T3 | Vocal-cord fixation and/or invasion of pre-epiglottic or paraglottic space, or inner cortex thyroid cartilage |
| T4a | Through thyroid cartilage and/or invasion beyond larynx |
| T4b | Prevertebral space, carotid encasement, or mediastinal structures |
B. Glottis
| T stage | Main point |
|---|---|
| T1 | Limited to vocal cord(s), normal mobility |
| T1a / T1b | One cord / both cords |
| T2 | Extends to supra- or subglottis and/or impaired cord mobility |
| T3 | Vocal-cord fixation and/or paraglottic space or inner thyroid cartilage invasion |
| T4a | Through thyroid cartilage or outside larynx |
| T4b | Prevertebral space, carotid encasement, or mediastinal involvement |
Laryngeal mnemonic
“Mobility matters.”
- Normal mobility, localized disease: T1
- Impaired mobility: T2
- Fixed cord: T3
- Cartilage through-and-through or extra-laryngeal spread: T4a
8. Distant metastasis
| M stage | Meaning |
|---|---|
| M0 | No distant metastasis |
| M1 | Distant metastasis present |
Common metastatic sites: lung, bone, liver.
One-page revision summary
| Feature | T1 | T2 | T3 | T4a | T4b |
|---|---|---|---|---|---|
| Most mucosal sites | Small localized tumor | Larger/local extension | Large tumor or functional impairment | Moderately advanced local invasion | Very advanced invasion |
| Oral cavity | ≤2 cm and DOI ≤5 mm | 2-4 cm or DOI 5-10 mm | >4 cm or DOI >10 mm | Bone/sinus/skin | Masticator space/skull base/carotid |
| Oropharynx | ≤2 cm | 2-4 cm | >4 cm/lingual epiglottis | Larynx, tongue muscle, mandible etc. | Skull base/carotid etc. |
| Larynx | Localized, mobile cord | Adjacent spread/impaired mobility | Fixed cord | Through cartilage/outside larynx | Prevertebral/carotid/mediastinum |
The core framework and oral cavity DOI criteria are described in K J Lee’s Essential Otolaryngology, pp. 776-777. The key distinctions in AJCC 8 are oral-cavity DOI, ENE in usual mucosal nodal staging, and separate HPV-mediated oropharyngeal staging.
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I may have given more detail than you wanted.
Do you want a single short exam table for:
- Oral cavity cancer only, or
- All common head and neck SCC sites: oral cavity, oropharynx, hypopharynx, larynx?
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"head and neck neoplasms" AND staging
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AJCC 8 head neck cancer staging oral cavity oropharynx hypopharynx larynx T classification
Head and Neck Cancer TNM: Rapid Revision Table
Common SCC sites: oral cavity, oropharynx, hypopharynx, larynx
First rule
| Component | Meaning | What to remember |
|---|---|---|
| T | Primary tumor | Varies by site |
| N | Cervical lymph nodes | Mostly common between sites |
| M | Distant metastasis | M0 no, M1 yes |
1. Common N stage: learn this first
For oral cavity, p16-negative oropharynx, hypopharynx, and larynx:
| Stage | Node criterion | Quick memory |
|---|---|---|
| N0 | No node metastasis | None |
| N1 | One ipsilateral node ≤3 cm, ENE negative | One, same side, ≤3 |
| N2a | One ipsilateral node >3 to ≤6 cm, ENE negative | One, 3-6 |
| N2b | Multiple ipsilateral nodes, none >6 cm, ENE negative | Many, same side |
| N2c | Bilateral or contralateral nodes, none >6 cm, ENE negative | Other side/both sides |
| N3a | Any node >6 cm, ENE negative | >6 |
| N3b | Any node with clinical ENE positive | ENE = N3b |
ENE = extranodal extension, meaning tumor has spread outside the lymph-node capsule.
N mnemonic
1 = one ≤3
2a = one 3-6
2b = bunch, same side
2c = crossing sides
3a = >6
3b = breaks capsule, ENE
2a = one 3-6
2b = bunch, same side
2c = crossing sides
3a = >6
3b = breaks capsule, ENE
2. T stage comparison: all common sites
| Stage | Oral cavity | Oropharynx, p16-negative | Hypopharynx | Larynx: general concept |
|---|---|---|---|---|
| T1 | ≤2 cm and DOI ≤5 mm | ≤2 cm | ≤2 cm, one subsite only | Small, localized lesion with normal cord mobility |
| T2 | ≤2 cm with DOI >5-10 mm or >2-4 cm with DOI ≤10 mm | >2 to ≤4 cm | >2 to ≤4 cm, or adjacent subsite involved | Adjacent spread and/or impaired cord mobility |
| T3 | >4 cm or DOI >10 mm | >4 cm or lingual surface of epiglottis | >4 cm, fixed hemilarynx, or esophageal mucosal extension | Vocal-cord fixation, paraglottic space or inner thyroid-cartilage involvement |
| T4a | Cortical bone, maxillary sinus, or facial skin invasion | Larynx, extrinsic tongue muscle, medial pterygoid, hard palate, or mandible | Cartilage, hyoid, thyroid gland, esophageal muscle, or central soft tissue | Through thyroid cartilage and/or spread outside larynx |
| T4b | Masticator space, pterygoid plates, skull base, or carotid encasement | Lateral pterygoid, pterygoid plates, lateral nasopharynx, skull base, or carotid encasement | Prevertebral fascia, carotid encasement, or mediastinum | Prevertebral space, carotid encasement, or mediastinal structures |
DOI = depth of invasion. It is used specifically in oral cavity carcinoma and is not the same as tumor thickness.
3. T4a versus T4b: easy differentiation
| T4a | T4b |
|---|---|
| Moderately advanced local disease | Very advanced local disease |
| Invades nearby structures | Invades deep critical structures |
| Bone, cartilage, skin, thyroid, larynx, tongue muscle, etc. | Skull base, prevertebral fascia, masticator space, carotid encasement, mediastinum |
| Usually potentially resectable depending on situation | Often unresectable or technically very difficult |
Quick mnemonic
- T4a = Adjacent structures
- T4b = Base of skull / Big vessels / Back of neck
4. Oral cavity: highest-yield table
| T stage | Size and DOI |
|---|---|
| T1 | ≤2 cm and DOI ≤5 mm |
| T2 | ≤2 cm with DOI >5-10 mm, or >2-4 cm with DOI ≤10 mm |
| T3 | >4 cm or DOI >10 mm |
| T4a | Bone, sinus, or skin invasion |
| T4b | Masticator space, pterygoid plate, skull base, carotid |
Oral cavity mnemonic: “2, 4, 10, then deep”
- 2 cm + 5 mm DOI = T1
- 2-4 cm or 5-10 mm DOI = T2
- >4 cm or >10 mm DOI = T3
- Deep invasion = T4
5. Larynx: most tested point
| Finding | T stage |
|---|---|
| Lesion localized, vocal cords mobile | T1 |
| Impaired vocal-cord mobility | T2 |
| Fixed vocal cord | T3 |
| Through thyroid cartilage / outside larynx | T4a |
| Carotid encasement, prevertebral or mediastinal invasion | T4b |
Larynx mnemonic
“Mobile - T1, impaired - T2, fixed - T3.”
6. HPV-positive oropharyngeal carcinoma: exception
p16-positive or HPV-mediated oropharyngeal cancer has a separate staging system. Do not apply the standard N2a/N2b/N2c/N3b table.
| Clinical N stage | Criteria |
|---|---|
| N0 | No nodes |
| N1 | One or more ipsilateral node(s), all ≤6 cm |
| N2 | Contralateral or bilateral nodes, all ≤6 cm |
| N3 | Any node >6 cm |
7. M stage
| Stage | Meaning |
|---|---|
| M0 | No distant metastasis |
| M1 | Distant metastasis present |
Common distant sites: lung, bone, liver.
Exam takeaway: Learn the common N table, oral-cavity DOI, laryngeal cord mobility, and the distinction between T4a versus T4b.
Source: K J Lee’s Essential Otolaryngology, pp. 776-778.
Source: K J Lee’s Essential Otolaryngology, pp. 776-778.
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