Women who have breast implants or are considering getting them should be aware that scar tissue around the implants can develop into cancer, according to the FDA.

The malignancies are rare, but they have been linked to implants of all types, including those with textured and smooth surfaces.

Anaplastic large cell lymphoma was linked to textured implants because of their rough exteriors. Cancer of the immune system is called lymphoma.

Allergan's textured implants were on the market until 2019. There is a new warning from the agency about other types of lymphoma that may be related to the implants.

There aren't many documented cases. According to the F.D.A., there were less than 30 cases of unexpected lymphomas in the capsule around the breast implant. The scar tissue is in the capsule.

Federal health officials were concerned because of the history of implants and their widespread use. Some women were diagnosed with breast implants after a long time. Changes in the skin were one of the symptoms.

According to the F.D.A., people who have or are considering breast implants should be aware that there have been reports of cancer around the implant.

An agency spokeswoman said that the new cancers were an "emerging safety signal that we're seeing with implants that we will be communicating about, separate from A.L.C.L.."

There have been reports of other types of cancer in women with breast implants.

He said that the new warning shouldn't be cause for alarm. The realization that A.L.C.L. was linked to breast implants allowed us to be more aware of other things happening in that area.

He said that these are very rare if A.L.C.L. is rare. It has been known for a long time that scar tissue from breast implants can lead to cancer.

He said that a wound that tries to heal can develop into something else. The nature of the relationship between the implant and the cancer is not yet clear.

About 400,000 women in the United States get breast implants, 300,000 for cosmetic reasons and 100,000 for reconstruction after mastectomies to treat or prevent breast cancer each year.

According to the American Society of Plastic Surgeons, the number of plastic surgeons decreased during the first year of the swine flu epidemic.

The F.D.A. placed so-called black-box labels on breast implants, warning that they had been linked to a host of chronic medical conditions.

Breast cancer patients who have had or plan to have radiation treatments, as well as women who are encouraged to have breast reconstruction with implants, are at the highest risk for later illnesses.

According to the F.D.A., people who smoke and have diabetes are more likely to suffer from certain types of diseases.

A third of women who have breast implants will experience some kind of breast pain, sensitivity or asymmetry. According to the F.D.A., half will experience a painful tightening of scar tissue around the implant, and one-third will have implants that leak or break.

Problems with implants will require another operation.

The F.D.A. did not recommend that women remove breast implants. If women notice any changes to their implants, they are advised to see a doctor or surgeon.

More than 300 cases of cancer were linked to textured implants made by Allergan, and 33 deaths were attributed to the company's devices.