What does an armpit lump feel like with breast cancer?

Some people notice a rounded or irregular area in the armpit, while others feel fullness rather than a distinct lump. The area may be painless, tender, or uncomfortable when the arm moves. These features can vary with the size and position of a lymph node and with the surrounding tissue.

Armpit Lump is a common presentation of Breast Cancer.

Breast cancer can involve lymph nodes in the armpit, which may become enlarged. An armpit lump can also arise from an infection, skin inflammation, a blocked gland, a recent vaccination, or another non-cancerous change. Tenderness, softness, or movement under the fingers does not reliably separate these causes. A clinician may examine both armpits and breasts, ask when the change began, and check for changes in the skin or nipple.

Arrange an appointment with a doctor or breast specialist for a new lump that persists, grows, or feels different from the other side. Note when you first noticed it, whether it changes during your menstrual cycle, and whether you have breast swelling, a new nipple change, or skin dimpling. Avoid repeatedly pressing the area, because this can make it sore and make changes harder to judge.

Assessment may include a physical examination and imaging such as an ultrasound or mammogram. If an area needs closer review, a tissue sample may be recommended. Only clinical assessment and, when needed, testing can establish the cause.

Seek prompt medical advice for an armpit lump with a new breast lump, nipple discharge that is bloody, nipple inversion, skin dimpling, marked redness, or swelling of the breast or arm. Get urgent help if the area is rapidly becoming painful and you also feel very unwell or have a high fever, as this can indicate an infection needing treatment.

You could ask: Could this be an enlarged lymph node or a skin-related lump? Which examination or scan is appropriate? What changes should prompt me to return sooner? If imaging is unclear, would a biopsy help explain the finding?