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The lump you experienced is most likely a swollen lymph
node. Armpit lumps may be caused by cysts, infection, or irritation due to shaving or using antiperspirants. However, these lumps may also indicate a serious health condition.
Seek medical attention if you have an armpit lump that gradually becomes enlarged, is not painful, or does not go away.A fine needle biopsy
of the lump is needed to reach the exact diagnosis after which treatment can be suggested.