Question: What is atypical hyperplasia and does it increase my risk for breast cancer?
Answer: Atypical hyperplasia is a condition that's found on a breast biopsy. In the breast there are cells that make up the normal glands of the breast itself. If those cells increase in number, we call that hyperplasia, which simply means "too many cells."
If those cells that are increased in number begin to look abnormal to the pathologist under the microscope when the pathologist looks at a biopsy, that condition is referred to as "atypia," which means that they look different than normal, but they're not quite yet meeting the criteria to be called cancer.
So atypical hyperplasia means too many abnormal-looking cells that are not yet cancer, but this condition, if found, increases the lifetime risk of developing breast cancer by about four- or five-fold.