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A lymph gland will become enlarged any time there is any infection or inflammation in the area that gland drains. It can take 2-3 weeks to return to normal size after an infection is completely cured (and an ear infection can take a month to cure). Even though the primary symptoms of the ear infection have resolved, there can still be inflammation which is a normal response of your immune system. Draining the area and clearing up the excess fluid and immune responders is the job of the lymph gland. You can mention the gland to your oncologist if it makes you feel better, but it is likely just a normal response to an ear infection. A sore throat will cause the same reaction, sometimes with lymph glands swollen all around the neck.
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