I agree, veterinary evaluation is in order; this may also be an aural hematoma (fluid filling the skin between the pinna and cartilage). Additionally, since your dog's ear problems occur frequently, there is likely an underlying allergic cause (food allergy or pollen/dust allergies), and consultation with a veterinary dermatologist (www.acvd.org) is recommended to help you identify and treat the cause of the problem.
Good luck,
Kimberly Coyner DVM DACVD
www.dermvetvegas.com
Sorry to hear about your dog. From the symptoms you describe, this could be a local infection (ear, salivary glands, skin), a tumor or a cyst. Your veterinarian could do a fine needle aspirate of the swelling to submit to a pathologist in an effort to obtain a definitive diagnosis. Once a diagnosis is made the appropriate treatment could be antibiotics and anti-inflammatory drugs, surgery or a combination of all 3. Due to the age and breed of your dog I would not recommend simple treatment without first obtaining a diagnosis.