The area inside the mouth is known as the oral cavity. This includes the area around the tongue as well as the teeth and gums in addition to the inside of the cheek. Cancer can occur at any of these sites and often presents with a lump or an ulcer. The lumps can be painful but are often free of any symptoms other than a lump. Neck lumps are often found in association with oral cancers so the combination of a hard neck lump and a mouth ulcer is concerning and lead to a quick review with your doctor.
The main risk factors for oral cavity cancers are smoking and alcohol. They are more common with age and also in male. Oral cavity cancers are usually treated with surgery first, and this may be followed up with further treatment such as radiation therapy or chemotherapy, depending on the case.