If there is a swelling under armpit and a small lump what could it be?
It could be a lipoma (benign fatty tumor - I had one) or it could be a swollen lymph node - if it is it, could be swollen from something as simple as a sore throat. You might also have a minor fever if it is.
If the swelling persists or the fever increases in the next couple of days, it might be a good idea to call a clinic or a doctor.
breast cancer in worst case scenario or possibly an ingrown hair
it must be a like a ant bite or any other kind of animal bite