What should you know about lipoma under armpit?

A lipoma is a soft-tissue growth made of mature fat cells. Under the armpit it may feel soft, slightly mobile, and separate from the skin. However, the area also contains lymph nodes, sweat glands, hair follicles, breast tissue, and muscle. An armpit lump therefore cannot be identified by touch alone.

A clinician will ask about its onset and change, examine both armpits and nearby areas, and check for infection, skin inflammation, arm symptoms, or breast changes when relevant. Imaging or another test may be recommended if the lump is deep, firm, fixed, growing, or diagnostically uncertain.

Book an appointment for a new or persistent armpit lump, particularly if you cannot tell whether it is in the skin or deeper tissue. Note its size and movement without repeatedly pressing it, and mention recent infections, vaccinations, shaving irritation, injuries, medicines, and breast or arm symptoms.

A confirmed, comfortable lipoma may be monitored. Removal can be discussed if it rubs against clothing, causes pain, restricts arm movement, grows, or creates ongoing uncertainty. Ask about the expected scar and the relationship of the lump to nerves, vessels, lymph nodes, and nearby breast tissue.

Seek prompt medical review for rapid enlargement, a hard or fixed lump, persistent pain, skin ulceration, arm swelling, numbness, weakness, unexplained weight change, fever, or a breast or nipple change. Seek urgent help for severe infection signs, rapidly spreading redness, or sudden arm swelling with breathing difficulty. These signs do not identify the cause, but they warrant timely assessment.

Does this lump feel like a lipoma or a lymph node? Is imaging needed, and what changes should I monitor? If removal is appropriate, how will you protect nearby nerves and vessels, and will the tissue be examined?