Missed breast cancer in two patients with prepectoral silicone gel breast implants following implant displacement mammography

Mammography is the primary method used for the early detection of breast cancer (1). In patients without breast implants, mammography usually involves two views in which the breast is compressed: a mediolateral oblique (MLO) view, where the breast is viewed from side to side, and a craniocaudal (CC) view, where the breast is viewed from top to bottom. The presence of silicone breast implants has been shown to interfere with complete imaging of the breast (2-9). Hayes and associates (4) showed that when standard compression views were used, a breast implant obscured 22% to 83% of visualizable breast tissue. To improve imaging in breast implant patients, Eklund et al (8) developed the implant displacement technique, in which the breast tissue is drawn anteriorly away from the implant and is compressed between the x-ray film holder and the paddle. When this technique was used in patients with breast implants and the results were compared with pre-augmentation films, the visualized area was still decreased, but only by 25% (5,6). Compression and displacement methods complement each other. Posterior breast tissue is visualized best with compression, and anterior tissue is seen best with displacement (7). Mammography centres currently recommend a four-view mammogram in patients with breast implants – the two standard compression views (MLO and CC) and the same views repeated using the implant displacement technique (10). The present report describes two patients who presented during the past year with a breast carcinoma that was missed following compression and displacement views and was discovered incidentally at the time of explantation of their implants.