Swollen submandibular gland, visible when swallowing duration: 10 months. no pain?

Swollen gland: What you describe should be evaluated. Without a one on one clinical exam and perhaps some tests we can't determine over the internet whether it is a chronically inflamed lymph node, enlarged salivary gland or some form of growth. See both a local dentist to determine if you have any dental infections and a physician for a proper evaluation.