Cellular breast enlargement. Light micrograph of a section through tissue from a hypertrophic breast. Hypertrophy is the enlargement of an organ through the enlargement of its cells, rather than from an increase in the number of its cells. The condition has here developed during puberty, but it can also arise following childbirth. It can be treated by mammoplasty (breast surgery) to reduce the size of the breasts. Magnification unknown.