What could cause a small lump that feels like a knot in the underarm of a man?

Answer by  Mike93 (8)

This could respresent an enlarged lymph node from a local infection. It could also be something more sinister such as a symptom from a variety of cancers. If the knot persists, I would consider having a professional look at it.

Answer by  DrGlove (23)

Of course you would want to check with your doctor because of your lymph glands being located under your arm. However besides something serious like cancer it can be as harmless as an enlarged sweat gland.

Answer by  ppisklak (33)

Some causes are benign (not too bad), but some good be cancerous. It could be a form of cancer (lymphoma or sarcoma or others). But it could just be an infected hair/sweat follicle. The only way to find out would be to have a doctor do a biopsy.

Answer by  Pancho (68)

An inflammation to the lymph node around your armpit could cause this condition. A friend of mine once had this condition and the doctors were afraid of lymphoma, a type of cancer. Sometimes the lumps mean nothing though.