Jessica Purcell, a captain in the U.S. Army Reserve, was pregnant with her first child when she noticed a swollen lymph node in her left underarm.

Health-care providers at a MacDill Air Force Base clinic told her it was likely an infection or something related to pregnancy hormones. The following year they determined the issue had resolved itself.

It hadn't. A doctor off base found a large mass in her underarm and gave her a shocking diagnosis: stage 2 breast cancer.

Purcell was pregnant again. Her daughter had just turned 1. She was 35. And she had no right to sue for malpractice.

A 1950 Supreme Court ruling known as the Feres doctrine prohibits military members like Purcell from filing a lawsuit against the federal government for any injuries suffered while on active duty. That includes injury in combat, but also rape and medical malpractice, such as missing a cancer diagnosis.

Thanks in part to Tampa lawyer Natalie Khawam, a provision in this year's national defense budget allows those in active duty to file medical malpractice claims against the government for the first time since the Feres case.

With the Department of Defense overseeing the new claims process, the question now is how fairly and timely complaints will be judged. And whether, in the long run, this new move will help growing efforts to overturn the ruling and allow active duty members to sue like everyone else.