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1.The possible cause in this case could be ductal ectasia ( dilated ducts). Next possible cause is adenomas - mass lesions,lastly
cyst.
2.In your age i would suspect ductal pathology - due to
hormonal imbalance, cyclical issue.
3.In this case i would recommend you to get an
ultrasound - non invasive, no
radiation scan for assessment of the lump.
4.Ultrasound will help to assess the nature of the lump, source and extensions. If mass lesion an FNAC - fine needle aspiration cytology will be helpful to assess the nature of the cells involved in the process.
5.I would recommend to see your GP, get examined,investigated and needful treatment. Good luck.
Hope i have answered your query,
any thing to ask do not hesitate to ask.
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