3 yr old has a lump on her right lower jawbone?

Hi,

Welcome to the ehealthforum and I am really glad to help you out. Your concern is regarding the lump under your grand daughter's jaw. The most common cause of such lump under the jaw is swollen lymph node. Lymph nodes are small (1-2cm) and bean-shaped nodes. Lymphadenopathy (swollen lymph nodes) is usually caused by a viral or bacterial infection. Other causes include allergic reactions, arthritis, cancer, metabolic diseases, and an overactive thyroid (hyperthyroidism).

The second possibility is of a salivary gland swelling. Any infection, stone or tumor of the salivary gland (submandibular gland) can cause a lump under the jaw. Third possibility is of a small cyst under the skin. My sincere advice is to consult a physician and get it evaluated. CT scan of the area and fine needle aspiration cytology and biopsy will help in confirming the diagnosis.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.