Small bump inside penis/urethra?

Yesterday my husband felt a small bump (he said maybe half the size of a pea) inside his penis. He said there is no discomfort of pain associated with is, and he hasn't had any burning, itching, or odd sensations when urinating.
I've been searching online, but haven't found anything. Any idea what this could be? Also, we try to avoid doctors at all costs, especially when dealing with a problem about which we are clueless.
Any advice or information would be greatly appreciated.
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