Squamous metaplasia on the breast implant capsule.

The development of squamous metaplasia or carcinoma is a rare occurrence in the setting of a ruptured or leaking silicone breast implant capsule. However, the oncogenic process in such a context is yet another intriguing example of how chronic inflammation plays an integral role in the tumorigenic process. Recent papers have shed light on how inflammation involving M2-tpe macrophages, lymphocytes, and other inflammatory cells at first provide the cytokines necessary to fend off an inciting foreign-body attack such as silicone from a ruptured or leaking implant. Although such a response is beneficial in keeping infection or foreign material in check, there are instances when the response may be exaggerated. It is thought that the extent and length of the response, the balance between pro-inflammatory/ anti-apoptotic and anti-inflammatory/pro-apoptotic, as well as genetic factors play important roles in determining the final result of an inflammatory insult.