An F.D.A. update in March that linked nine deaths to the implants has helped raise awareness. The agency had received 359 reports of implant-associated lymphoma from around the world, although the actual tally of cases is unknown because the F.D.A.’s monitoring system relies on voluntary reports from doctors or patients. The number is expected to rise as more doctors and pathologists recognize the connection between the implants and the disease.

Women who have had the lymphoma say that the attention is long overdue, that too few women have been informed of the risk and that those with symptoms often face delays and mistakes in diagnosis, and difficulties in receiving proper care. Some have become severely ill.

Implants have become increasingly popular. From 2000 to 2016, the number of breast augmentations in the United States rose 37 percent, and reconstructions after mastectomy rose 39 percent. Annually, nearly 400,000 women in the United States get breast implants, about 300,000 for cosmetic enlargement and about 100,000 for reconstruction after cancer, according to the American Society of Plastic Surgeons. Allergan and Mentor are the major manufacturers. Worldwide, an estimated 1.4 million women got implants in 2015.