Is teething can cause enlarged lymph node behind/middle part left ear??

No. Please see Dentist to evaluate "teething," and Physician to investigate swelling behind ear. Probably not related, but all pain, bleeding, or swelling should be immediately investigated.
Swollen Glands. The lymph nodes behind the ear usually become enlarged if there are issues with the ear, pinna, or sections of the scalp. Anything as simple as an insect bite, scratch, irritated dry skin can lead to the enlarged node you are noticing. If it becomes very swollen or isn't resolving have a physician examine it.

Related Questions

I have an enlarged lymph node under my left ear could this be a cyst? And why did it just randomly pop up? How can I make it go away?

Facial mass. Masses of the head and neck need to be checked out by your primary care doctor. This could be anything from a lymph node to a parotid gland mass to a infected cyst. Without a proper history and physical from your doctor, there is no way to know exactly what it is. Go see your physician. Read more...
Get it checked. Difficult to say why anything like that "pops up" with no reason. There are typically causes of these types of things, and a review of the history with your doctor can help reveal the cause and the solution to the problem. See a doctor soon. Read more...