Doctors can often determine if a swollen lymph node is likely cancerous based on a physical exam, but tests are usually needed to confirm a diagnosis. Here are some quick answers about how doctors evaluate lymph nodes for cancer:
What causes swollen lymph nodes?
Lymph nodes commonly swell due to infections, inflammation, or cancer. Infections account for most cases of swollen lymph nodes. Cancer is a less common cause, but is important to rule out.
How do doctors check lymph nodes?
Doctors physically examine all lymph node areas, feeling for any enlarged nodes. They check areas including the neck, underarms, groin, abdomen, and chest. If nodes feel enlarged, the doctor will note their features, including size, shape, firmness, mobility, warmth, and tenderness.
Can enlarged lymph nodes be a sign of cancer?
Yes, sometimes cancer will cause lymph nodes near a tumor to swell as they fill with cancer cells. Lymphoma and leukemias also directly arise from lymph nodes or bone marrow and make lymph nodes expand. In general, the larger the node and the harder, less movable, and more clustered it feels, the more concerning for cancer.
Which cancers commonly spread to lymph nodes?
| Cancer Type | Lymph Nodes Often Affected |
|---|---|
| Breast cancer | Underarm lymph nodes |
| Melanoma | Lymph nodes near original skin site |
| Head and neck cancers | Neck lymph nodes |
| Lymphomas | Nodes throughout body |
Cancers like breast, skin, and head/neck tend to spread to nearby draining lymph nodes early on. Checking these lymph nodes can provide key information about prognosis and guide treatment.
What tests further evaluate swollen lymph nodes?
If lymph nodes seem suspicious for cancer, doctors may recommend:
- Ultrasound – to assess node features and guide possible biopsy
- Needle biopsy – removes cells to examine under a microscope
- Surgical biopsy – removes entire lymph node for examination
- PET/CT scan – highlights metabolically active nodes concerning for cancer
Doctors choose tests based on the lymph node location and characteristics, along with patient factors like medical history. Examining lymph node tissue is key to diagnosis.
How accurate are these methods for detecting cancer?
No test is 100% accurate, but evaluating lymph nodes for cancer is generally quite reliable when done thoroughly. Research suggests:
- Careful physical exam by an experienced doctor detects concerning nodes with about 70% accuracy
- Adding ultrasound improves detection to over 90% accuracy
- Biopsy provides a near 100% accurate diagnosis
Following up initial findings with imaging tests and biopsy allows doctors to determine with a high degree of certainty whether cancer is present in lymph nodes.
What happens if lymph nodes have cancer?
Finding cancer in one or more lymph nodes typically indicates:
- The cancer originated nearby where the affected nodes are located
- The cancer has started spreading to other body parts
- More intensive treatment like surgery, chemo, or radiation will be needed
Checking lymph nodes is important for cancer staging. Positive lymph nodes mean the cancer is at least stage II. Treatment plans are guided by the stage and aggressiveness of the cancer.
Can lymph node enlargement be benign?
Yes, more than half of enlarged lymph nodes are benign. Common causes include:
- Infections – bacterial, viral, fungal
- Inflammation and autoimmune conditions
- Reactive lymph nodes after vaccination or injury/trauma
- Hyperplasia or other non-cancerous growths
With normal/reactive nodes, features like being small, soft, movable, and tender point away from cancer. Biopsy can definitively diagnose non-cancerous enlargement.
Conclusion
Doctors have reliable methods to determine if lymph nodes are enlarged due to cancer or benign causes. Careful physical examination combined with imaging tests and biopsy allows for accurate diagnosis. Finding cancer in lymph nodes affects cancer staging and treatment planning. Benign lymph node enlargement is typically managed by treating underlying inflammation or infection.