hi. based from your description, it could be a possible cervical lymphadenopathy (inflamed lymph node) probably secondary to a recent upper respiratory tract infection; a possible lesion of thyroid or salivary gland in origin. thyroglossal duct cyst and other considerations like fibroma, lipoma or cystic formation must also be ruled-out. it is best if you consult with a doctor for physical examination and clinical evaluation. diagnostic examinations such as neck ultrasound, ct-scan or x-ray, thyroid function tests and tissue biopsy may be recommended as needed. subsequent management (medical and/or surgical if indications are found) will be directed accordingly. hope this helps. good day!! ~dr.kaye