Do lymph nodes become swollen from a benign tumor in the breast?

Yes, benign tumors in the breast can cause lymph nodes to become swollen. Typically, this occurs when cells from the tumor spread through the lymphatic system, a network of vessels transporting sources of infection and cancer throughout the body. This process is called metastasis and is the most common form of breast cancer spread.

The body responds to these spreading cells by producing more white blood cells as part of an immune response—which increases pressure against nearby tissue, including any nearby lymph nodes. This causes them to swell in size, resulting in what doctors call "lymphadenopathy". Ultimately though it's important to note that not all swollen lymph nodes are caused by a tumor; they may be due to other infections or medical conditions as well. Therefore it's important for anyone experiencing swelling around their breasts or underarms to seek prompt medical attention to receive proper diagnosis and treatment care.