Pharynx

TNM 7 classification

TNM 6 classification

1. Rules for Classification

The classification applies only to carcinomas. There should be histological confirmation of the disease.

The following are the procedures for assessing T, N, and M categories:

T categories. Physical examination, endoscopy and imaging
N categories. Physical examination and imaging
M categories. Physical examination and imaging

2. Anatomical Sites and Subsites

Oropharynx (C01, C05.1, 2, C09.0, 1, 9, C10.0, 2, 3)

1. Anterior wall (glosso-epiglottic area)
   i. Base of tongue (posterior to the vallate papillae or posterior third) (C01)
   ii. Vallecula (C10.0)
   
2. Lateral wall (C10.2)
   i. Tonsil (C09.9)
   ii. Tonsillar fossa (C09.0) and tonsillar (faucial) pillars (C09.1)
   iii. Glossotonsillar sulci (tonsillar pillars ) (C09.1)
   
3. Posterior wall (C10.3)
   
4. Superior wall
   i. Inferior surface of soft palate (C05.1)
   ii. Uvula (C05.2)
   

Nasopharynx (C11)

1. Postero-superior wall: extends from the level of the junction of the hard and soft palates to the base of the skull (C11.0, 1)
   
2. Lateral wall: including the fossa of Rosenmüller (C11.2)
   
3. Inferior wall: consists of the superior surface of the soft palate (C11.3)
   

Note: The margin of the choanal orifices, including the posterior margin of the nasal septum, is included with the nasal fossa.

Hypopharynx (C12, C13)

1. Pharyngo-oesophageal junction (postcricoid area) (C13.0): extends from the level of the arytenoid cartilages and connecting folds to the inferior border of the cricoid cartilage, thus forming the anterior wall of the hypopharynx
   
2. Piriform sinus (C12.9): extends from the pharyngo-epiglottic fold to the upper end of the oesophagus. It is bounded laterally by the thyroid cartilage and medially by the hypopharyngeal surface of the aryepiglottic fold (C13.1) and the arytenoid and cricoid cartilages
   
3. Posterior pharyngeal wall (C13.2): extends from the superior level of the hyoid bone (or floor of the vallecula) to the level of the inferior border of the cricoid cartilage and from the apex of one piriform sinus to the other
   

3. Regional Lymph Nodes

The regional lymph nodes are the cervical nodes.
The supraclavicular fossa (relevant to classifying nasopharyngeal carcinoma) is the triangular region defined by three points: (1) the superior margin of the sternal end of the clavicle; (2) the superior margin of the lateral end of the clavicle; (3) the point where the neck meets the shoulder. This includes caudal portions of Levels IV and V.

4. TNM Clinical Classification

4.1. T - Primary Tumour

TX. Primary tumour cannot be assessed
T0. No evidence of primary tumour
Tis. Carcinoma in situ

4.1.1. Oropharynx

T1. Tumour 2 cm or less in greatest dimension
T2. Tumour more than 2 cm but not more than 4 cm in greatest dimension
T3. Tumour more than 4 cm in greatest dimension
T4a. Tumour invades any of the following: larynx deep/ extrinsic muscle of tongue (genioglossus, hyoglossus, palatoglossus, and styloglossus), medial pterygoid, hard palate, and mandible
T4b. Tumour invades any of the following: lateral pterygoid muscle, pterygoid plates, lateral nasopharynx, skull base; or encases the carotid artery

4.1.2. Nasopharynx

T1. Tumour confined to nasopharynx
T2. Tumour extends to soft tissues
T2a. Tumour extends to oropharynx and/or nasal cavity without parapharyngeal extension*
T2b. Tumour with parapharyngeal extension*
T3. Tumour invades bony structures and/or paranasal sinuses
T4. Tumour with intracranial extension and/or involvement of cranial nerves, infratemporal fossa, hypopharynx, orbit, or masticator space

4.1.3. Hypopharynx

T1. Tumour limited to one subsite of hypopharynx (see T - Primary Tumour) and 2 cm or less in greatest dimension
T2. Tumour invades more than one subsite of hypopharynx or an adjacent site, or measures more than 2 cm but not more than 4 cm in greatest dimension, without fixation of hemilarynx
T3. Tumour more than 4 cm in greatest dimension, or with fixation of hemilarynx
T4a. Tumour invades any of the following: thyroid/cricoid cartilage, hyoid bone, thyroid gland, oesophagus, central compartment soft tissue*
T4b. Tumour invades prevertebral fascia, encases carotid artery, or invades mediastinal structures

4.2. N - Regional Lymph Nodes (Oro- and Hypopharynx)

NX. Regional lymph nodes cannot be assessed
N0. No regional lymph node metastasis
N1. Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension
N2. Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension; or in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension; or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension
N2a. Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension
N2b. Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest dimension
N2c. Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension
N3. Metastasis in a lymph node more than 6 cm in greatest dimension

Note: Midline nodes are considered ipsilateral nodes.

4.3. N - Regional Lymph Nodes (Nasopharynx)

NX. Regional lymph nodes cannot be assessed
N0. No regional lymph node metastasis
N1. Unilateral metastasis, in lymph node(s), 6 cm or less in greatest dimension, above the supraclavicular fossa
N2. Bilateral metastasis in lymph node(s), 6 cm or less in greatest dimension, above the supraclavicular fossa
N3. Metastasis in lymph node(s) greater than 6 cm in dimension or in the supraclavicular fossa
    N3a. greater than 6 cm in dimension
    N3b. in the supraclavicular fossa
Note: Midline nodes are considered ipsilateral nodes.

4.4. M - Distant Metastasis

MX. Distant metastasis cannot be assessed
M0. No distant metastasis
M1. Distant metastasis

5. pTNM Pathological Classification

The pT, pN, and pM categories correspond to the T, N, and M categories.

pN0. Histological examination of a selective neck dissection specimen will ordinarily include 6 or more lymph nodes. Histological examination of a radical or modified radical neck dissection specimen will ordinarily include 10 or more lymph nodes. If the lymph nodes are negative, but the number ordinarily examined is not met, classify as pN0. When size is a criterion for pN classification, measurement is made of the metastasis, not of the entire lymph node.

6. G Histopathological Grading

See definitions here.

7. Stage Grouping (Oropharynx and Hypopharynx)

Stage 0 Tis N0 M0 Stage I T1 N0 M0 Stage II T2 N0 M0 Stage III T1, T2 N1 M0 T3 N0, N1 M0 Stage IVA T1,T2,T3 N2 M0 T4a N0, N1, N2 M0 Stage IVB T4b Any N M0 Any T N3 M0 Stage IVC Any T Any N M1

8. Stage Grouping (Nasopharynx)

Stage 0 Tis N0 M0 Stage I T1 N0 M0 Stage IIA T2a N0 M0 Stage IIB T1 N1 M0 T2a N1 M0 T2b N0, N1 M0 Stage III T1 N2 M0 T2a, T2b N2 M0 T3 N0, N1, N2 M0 Stage IVA T4 N0, N1, N2 M0 Stage IVB Any T N3 M0 Stage IVC Any T Any N M1

9. Summary

Pharynx Oropharynx T1 ≤2 cm T2 >2 to 4 cm T3 >4 cm T4a Larynx, deep/extrinsic muscle of tongue, medial pterygoid, hard palate, mandible T4b Lateral pterygoid muscle, pterygoid plates, lateral nasopharyns, skull base, carotid artery. Hypopharynx T1 ≤2 cm and limited to one subsite T2 >2 to 4 cm or more than one subsite T3 >4 cm or with hemilarynx fixation T4a Thyroid/cricoid cartilage, hyoid bone, thyroid gland, oesophagus, central compartment soft tissue T4b Prevertebral fascia, carotid artery, mediastinal structures Oropharynx and Hypopharynx N1 Ipsilateral single ≤3 cm N2 (a) Ipsilateral single >3 to 6 cm (b) Ipsilateral multiple ≤6 cm (c) Bilateral, contralateral ≤6 cm N3 >6 cm Nasopharynx T1 Nasopharynx T2 Soft tissue T2a Oropharynx/nasal cavity without parapharyngeal extension T2b Tumour with parapharyngeal extension T3 Bony structures, paranasal sinuses T4 Intracranial, cranial nerves, infratemporal fossa, hypopharynx, orbit, masticator space N1 Unilateral node(s) ≤6 cm, above supraclavicular fossa N2 Bilateral node(s) ≤6 cm, above supraclavicular fossa N3 (a) >6 cm (b) in supraclavicular fossa