Malignant disease conditions 

Hepatocellular carcinoma (HCC) is the most common primary malignant tumour of the liver, arising from hepatocytes. It represents a major cause of cancer-related morbidity and mortality worldwide, particularly in regions with a high prevalence of chronic viral hepatitis infection.

Gastric cancer is a malignant tumour arising from the epithelial lining of the stomach. It is one of the major gastrointestinal malignancies and remains a significant cause of cancer-related morbidity and mortality worldwide.

Esophageal cancer is a malignant tumour arising from the epithelial lining of the oesophagus, the muscular tube that transports food from the pharynx to the stomach. It is an aggressive malignancy associated with late presentation, rapid progression, and poor overall survival.

Thyroid carcinoma is a malignant tumour arising from the thyroid gland, an endocrine organ located in the anterior neck responsible for production of thyroid hormones. It is the most common endocrine malignancy and represents a heterogeneous group of cancers with different biological behaviours, treatment responses, and prognoses.

Oropharynx is located between the soft palate superiorly and the hyoid bone inferiorly. The oropharynx has four walls; soft palate, tonsillar region, base of tongue, and pharyngeal wall.