During my postgraduate training, a woman who lived in my neighbourhood approached me with a concern. She had noticed a hard lump in her armpit.
When I examined her, there was no obvious lump in the breast. Situations like this can sometimes be confusing, but the firm nature of the lump raised suspicion. Instead of assuming it was a simple swollen lymph node, I advised her to undergo radiological evaluation immediately.
Further investigations confirmed that the lump was related to breast cancer involving the axillary lymph nodes. She underwent complete treatment, including surgery and other necessary therapies, and thankfully she recovered well.
This experience stayed with me because it reminded me that sometimes the body gives clues in unexpected places.
Why Can a Lump Appear in the Armpit?
The breast has an extensive lymphatic drainage system. Nearly three-quarters of lymph from the breast drains to the lymph nodes in the armpit, also called the axillary lymph nodes.
These lymph nodes act as filters in the lymphatic system. When cancer develops in the breast, malignant cells can travel through these lymphatic channels and reach these lymph nodes. As a result, the lymph nodes may enlarge and present as a lump in the armpit.
In rare situations, this enlargement may appear before a lump in the breast becomes clinically detectable. Doctors sometimes describe this as occult breast cancer, where the primary tumor in the breast is very small or difficult to detect initially.
Features of Axillary Lumps That Need Attention
Not every lump in the armpit is related to breast cancer. However, certain features may require medical evaluation. A suspicious lymph node may feel hard or firm, may be non-tender, may have an irregular surface, may appear fixed rather than freely movable, or may persist and gradually increase in size.
When such features are present, doctors usually recommend further evaluation with imaging tests such as ultrasound or mammography, and sometimes a biopsy if required.
Most Armpit Lumps Are Benign
Fortunately, the majority of lumps in the armpit are not cancer. Common causes include swollen lymph nodes due to infections, sebaceous cysts, lipomas (fatty lumps), blocked sweat glands, and local skin infections.
Because these conditions are common, it is important not to immediately assume the worst when a lump is noticed.A Message for the PublicI am sharing this information for awareness and education, not to scare or create fear. A lump in the armpit does not automatically mean breast cancer, but any persistent or unusual lump should be examined by a doctor.
The safest approach is simple: do not panic, do not ignore it, and get it checked.
Footnote
Recently, another woman came to see me with a lump in her armpit. She was extremely worried after watching several YouTube videos suggesting that armpit lumps could indicate breast cancer.
After examining her, I found that the lump was actually a simple sebaceous cyst, which is a common and harmless condition. This was also a reminder that information on the internet can sometimes create unnecessary fear, and proper medical evaluation is always the best way to understand the real cause.