There are different views regarding the involvement of regional lymph nodes in metastasis. Metastasis is a complex process involving the detachment of cells from the tumour tissue, the regulation of cell motility and invasion, and the proliferation and evasion through the lymphatic system or blood vessels. The most deadly aspect of any cancer is its ability to spread or metastasize. Mechanism of metastases in head and neck cancer The diagnosis of such cervical neck tumours can be decided after a complete clinical and radiological examination, focusing on the organs or areas where there is a high chance of an existing primary tumour.Ģ. However, in unusual cases, they represent secondary tumours from primary sites below the clavicles. The common cause of metastatic cervical lymphadenopathy is the spread from primary tumours in the head and neck region. Therefore, it is important to assess as reliably as possible whether or not a patient has regional lymph node metastases. Patients with metastasis need more aggressive treatments. Moreover, the presence of another metastatic node on the contralateral side further reduces the survival rate by 25%. It is stated that the presence of metastatic node reduces the 5-year survival rate by 50%. This is because the therapeutic rational and prognosis depend on the staging of the cancer. The determination of the presence or absence of metastases in the neck nodes is mandatory for cancer-bearing patients. Lesions classed as T1 may show a regional spread in 10 to 20% of cases, T2 lesions in 25 to 30% of cases and T3 to T4 tumours in 50 to 75%. The incidence of spread is influenced by the size of the tumour. However, its spreading to contralateral nodes is more common with midline and posterior lesions.

Ipsilateral lymph nodes metastases are frequent. Oral cancer occurring in the posterior aspect of the oral cavity, oropharynx and inferior of the mouth tends to be associated with a higher incidence of spread to the lymph nodes at the time of diagnosis. In oral cancer, tumour dissemination occurs via regional lymphatic to cervical lymph node in a predictable and sequential fashion. Reports from the American Cancer Society indicate that, at the time of initial diagnosis, over 40% of patients with squamous cell carcinomas of the oral cavity and pharynx present with regional dissemination of the disease. Since squamous cell carcinoma constitutes the preponderance of primary malignancies of the head and neck, it is by far the most common tumour that spreads to the cervical nodes. It has a significant recurrence rate and frequently metastasizes to cervical lymph nodes. Oral squamous cell carcinoma is an invasive lesion with the presence of perineural growth. Squamous cell carcinoma is the most frequent single entity, constituting 95% of all oral malignancies. Amongst those, oral cancer is the most common type of cancer. These represent about 6% of all cancer cases and account for a number of new cancer cases and cancer-related deaths worldwide every year. Head and neck cancer refers to epithelial malignancies of various parts of the orofacial region, which include paranasal sinuses, nasal cavity, pharynx and larynx, etc.

7 levels of lymph nodes in neck