From the Guidelines
The staging of sinonasal mucosal melanoma is based on the American Joint Committee on Cancer (AJCC) Staging Manual (7th edition), which recognizes the disease's poor prognosis and gradation of survival based on the burden of disease, as reflected in local, regional, and distant extent. The AJCC staging system for mucosal melanoma begins with stage III disease as the most limited form of disease, and breaks the disease down into stages reflecting local burden of disease and regional and distant extent 1.
Key Staging Factors
- Melanomas confined to the mucosa only are classified as T3
- Those with moderately advanced lesions (involving underlying cartilage or bone) are classified as T4a
- Very advanced primary tumors are classified as T4b
- Nodal staging includes N0 (no regional lymph node metastasis), N1 (regional lymph node metastases present)
- Distant metastasis is classified as M0 (absent) or M1 (present) The AJCC staging system reflects the fact that mucosal melanoma occurs at all mucosal sites in the head and neck, and therefore, rules for classifying and staging, and surgical principles should be based on the appropriate anatomic site of origin 1.
Clinical Implications
- The staging system directly impacts treatment planning, which typically involves surgical resection when possible, often followed by radiation therapy and consideration of systemic therapy including immunotherapy
- The typically advanced presentation and poor prognosis of sinonasal mucosal melanoma, with most cases diagnosed at advanced stages due to the hidden anatomical location and nonspecific early symptoms, are taken into account in the staging system 1.
From the Research
Staging of Sinonasal Mucosal Melanoma
The staging of sinonasal mucosal melanoma is based on two different staging systems proposed by the American Joint Committee on Cancer (AJCC) 2. These systems include:
- One for carcinoma of the nasal cavity and sinuses
- The other for head and neck melanoma
AJCC Staging Systems
The AJCC 2002 staging system has been shown to have a statistically significant prognostic value (P=0.0476) in patients with sinonasal mucosal melanoma, whereas the AJCC 2009 staging system did not demonstrate a statistically significant prognostic value (P=0.108) 3.
Key Points
Some key points to consider in the staging of sinonasal mucosal melanoma include:
- The tumor site, with paranasal sinus invasion being significantly associated with a poor prognosis (P=0.0039) 3
- The use of imaging modalities such as FDG-PET/MRI for whole-body staging and assessment of distant metastases 4
- The importance of considering the clinical characteristics, progression, and treatment of the disease in determining the prognosis and management of sinonasal mucosal melanoma 5
Prognostic Factors
Prognostic factors for sinonasal mucosal melanoma include:
- Tumor site and extent of invasion
- Presence of regional lymph node metastasis
- Clinical symptoms such as headache, facial pain, and trigeminal V2 nerve anesthesia, which are associated with poor prognosis 5
- The use of adjuvant radiation therapy, which may show a non-significant trend toward improved local control 5