Can persistent swelling of the submandibular lymph nodes turn into cancer?

In general, whether persistent swelling of submandibular lymph nodes may turn into cancer depends on the specific underlying cause. Swelling caused by infection usually does not lead to cancer; however, if the swelling is triggered by malignant tumors such as lymphoma, thyroid cancer, or oral cancer, there is a possibility of malignancy. It is recommended to seek medical attention promptly, identify the cause, and receive appropriate treatment under the guidance of a qualified physician. Detailed analysis is as follows:

When the body is affected by pathogens such as bacteria or viruses, the immune system activates its defense mechanisms, including lymph node enlargement to combat the invaders. This type of swelling is a normal immune response aimed at containing the spread of pathogens and facilitating resolution of inflammation. Once the infection is controlled, the lymph nodes typically return gradually to their normal size. Therefore, submandibular lymph node swelling caused by infection does not directly transform into cancer.

Malignant tumor cells—such as those in lymphoma, thyroid cancer, or oral cancer—are invasive and can metastasize through the lymphatic or circulatory systems to the submandibular lymph nodes, causing them to swell. This swelling indicates progression of the malignancy, showing that cancer cells have already invaded the lymph nodes. In such cases, the swollen submandibular lymph nodes will not resolve spontaneously and may continue to enlarge as the disease worsens, potentially leading to further malignant changes.

To accurately determine the underlying cause, doctors may recommend diagnostic tests such as ultrasound, CT scans, MRI, or lymph node biopsy.