invasive lobular carcinoma. this single mom has breast cancer. she gets a second opinion.ore experts look at her lab work and agree. derry decides she has to be aggressive to save her life. she has surgery to remove both her breasts. and then weeks later a bombshell admission by her doctors. >> they told me basically you didn't have cancer and you never did. >> what makes doctors think she's sick? that biopsy showing she has cancer actually belongs to someone else. a health department investigation says a lab technician is most likely working with two specimens at the same time. by mistake the worker takes another woman's tissue and puts it inside a container labeled with darrie's identification. >> something should have been done to tell me that there wasn't anything wrong with me before i had a radical double mastectomy. >> you make the diagnosis with a biopsy, and for sure there could be a domino or butterfly effect that occurs from having a mistake in that initial biopsy where everybody starts to make a decision based on that initial biopsy or error. >> 1 out of 1,000