I don't want to scare anyone though, because a dilated duct doesn't always mean cancer. It just means that there might be a growth there. Growths in the lymph ducts are often benign but sometimes they're not. A biopsy has to be done to make sure.
The most important thing is to see a doctor when symptoms start because early diagnosis is so important when it comes to malignant tumors. Cancer in the lymphatic system is particularly dangerous because it can easily spread to the whole system since everything is connected.