Survivor since 2007
Invasive lobular carcinoma starts in the milk forming lobules on the breast. I think you are also asking about invasive ductal carcinoma which is breast cancer that starts out in the "tubes" which carry milk from the lobules.
Lobular cancer only makes up a small percentage of breast cancer. It doesn't, typically, start out as a lump but as a bulging or thickening of the breast.
Ductal cancer is the most common type of breast cancer making up about 80% of all breast cancers found. It does form a lump which can be felt.
There are different types of breast cancers and individual treatments for each of them. It also depends on the staging, and the individual cells seen microscopically. I hope this has helped. There are many sites on the internet you can refer to but probably the best is the American Cancer Society and The National Institute Of Health.