Why do one have a painful lump in armpit? – Dr. Nanda Rajaneesh

Painful lump in the skin area could be most often infection, inflammation of the skin area or it could be infection inflammation of the lymph nodes of the axilla which is very common. Other reasons could be an accessory breast which is having a mastitis in that part of the breast tissue. It may be infected or for some reason it may be increasing in size which can lead to pain in the armpit. So if you think it is a lymph node that is enlarging causing pain and you have another lump in the breast it could be a metastaic breast cancer with a nodal disease which may be compressing the nerves. There could be multiple enlargement of the axilla. You can get nodal enlargements due to lymphomas in the axilla but lymphomas may manifest as painless lumps in the axilla. But when they become very big in size they can become painful.