TNM Definitions
AJCC Stage Groupings

The staging systems are clinical estimates of the extent of disease. The assessment of the tumor is based on inspection, palpation, and direct endoscopy when necessary. The tumor must be confirmed histologically, and any other pathological data obtained on biopsy may be included. The appropriate nodal drainage areas are examined by careful palpation. Computed tomographic and/or magnetic resonance imaging studies are generally required to adequately evaluate tumor extent prior to attempted surgical resection or definitive radiation therapy. If a patient relapses, complete restaging must be done to select the appropriate additional therapy.[1,2]

Staging of nasal cavity and paranasal sinus carcinomas is not as well established as for other head and neck tumors. For cancer of the maxillary sinus, the nasal cavity, and the ethmoid sinus, the American Joint Committee on Cancer (AJCC) has designated staging by TNM classification.[3]

Maxillary sinus

Primary tumor (T)

• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• Tis: Carcinoma in situ
• T1: Tumor limited to maxillary sinus mucosa with no erosion or destruction of bone
• T2: Tumor causing bone erosion or destruction including extension into the hard palate and/or the middle of the nasal meatus, except extension to the posterior wall of maxillary sinus and pterygoid plates
• T3: Tumor invades any of the following: bone of the posterior wall of maxillary sinus, subcutaneous tissues, floor or medial wall of orbit, pterygoid fossa, ethmoid sinuses
• T4a: Tumor invades anterior orbital contents, skin of cheek, pterygoid plates, infratemporal fossa, cribriform plate, sphenoid or frontal sinuses
• T4b: Tumor invades any of the following: orbital apex, dura, brain, middle cranial fossa, cranial nerves other than maxillary division of trigeminal nerve (V₂), nasopharynx, or clivus

Nasal cavity and ethmoid sinus

Primary tumor (T)

• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• Tis: Carcinoma in situ
• T1: Tumor restricted to any one subsite, with or without bony invasion
• T2: Tumor invading two subsites in a single region or extending to involve an adjacent region within the nasoethmoidal complex, with or without bony invasion
• T3: Tumor extends to invade the medial wall or floor of the orbit, maxillary sinus, palate, or cribriform plate
• T4a: Tumor invades any of the following: anterior orbital contents, skin of nose or cheek, minimal extension to anterior cranial fossa, pterygoid plates, sphenoid or frontal sinuses
• T4b: Tumor invades any of the following: orbital apex, dura, brain, middle cranial fossa, cranial nerves other than (V₂), nasopharynx, or clivus

Regional lymph nodes (N)

• 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 6 cm or less in greatest dimension, or in multiple ipsilateral lymph nodes, 6 cm or less in greatest dimension, or in bilateral or contralateral lymph nodes, 6 cm or less in greatest dimension
  • N2a: Metastasis in a single ipsilateral lymph node more than 3 cm but 6 cm or less in greatest dimension
  • N2b: Metastasis in multiple ipsilateral lymph nodes, 6 cm or less in greatest dimension
  • N2c: Metastasis in bilateral or contralateral lymph nodes, 6 cm or less in greatest dimension
• N3: Metastasis in a lymph node more than 6 cm in greatest dimension

In clinical evaluation, the actual size of the nodal mass should be measured, and allowance should be made for intervening soft tissues. Most masses more than 3 cm in diameter are not single nodes but confluent nodes or tumors in soft tissues of the neck. There are three stages of clinically positive nodes: N1, N2, and N3. The use of subgroups a, b, and c is not required but is recommended. Midline nodes are considered homolateral nodes.

Distant metastasis (M)

• MX: Distant metastasis cannot be assessed
• M0: No distant metastasis
• M1: Distant metastasis

Stage 0

• Tis, N0, M0

Stage I

• T1, N0, M0

Stage II

• T2, N0, M0

Stage III

• T3, N0, M0
• T1, N1, M0
• T2, N1, M0
• T3, N1, M0

Stage IVA

• T4a, N0, M0
• T4a, N1, M0
• T1, N2, M0
• T2, N2, M0
• T3, N2, M0
• T4a, N2, M0

Stage IVB

• T4b, any N, M0
• Any T, N3, M0

Stage IVC

• Any T, any N, M1

References

1. Mendenhall WM, Riggs CE Jr, Cassisi NJ: Treatment of head and neck cancers. In: DeVita VT Jr, Hellman S, Rosenberg SA, eds.: Cancer: Principles and Practice of Oncology. 7th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2005, pp 662-732. 
   
   
2. Laramore GE, ed.: Radiation Therapy of Head and Neck Cancer. Berlin: Springer-Verlag, 1989. 
   
   
3. Nasal cavity and paranasal sinuses. In: American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002, pp 59-67. 
   
   

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