What is the difference between a lumpectomy and a mastectomy?

Partial vs total: A lumpectomy is the removal of the breast tumor (the "lump") and some of the normal tissue that surrounds it. Lumpectomy is a form of "breast-conserving" surgery. A mastectomy is the removal of the entire breast tissue. The main types of mastectomy are: "simple" or "total" mastectomy, modified radical mastectomy, and radical mastectomy.

Breast conservation?: Lumpectomy or partial/segmental mastectomy refers to removal of the tumor with a rim or margin of normal tissue but conservation of the breast and almost always is followed by radiation. The goal of mastectomy is to remove all the glandular tissue. Skin sparing with immediate reconstruction preserves the skin envelop. Nipple sparing may be an option for smaller tumors away from the nipple.