Washington Redskins left tackle, Trent Williams, initially noticed a lump on his head in 2013. The lump continued to grow substantially over the last six years, but Williams said despite his concern, it was repeatedly dismissed as benign.

During the past offseason, Williams was going to have the lump, thought to be a cyst, removed. It was then he found out that the situation was more serious. Williams was diagnosed with dermatofibrosarcoma protuberans, or DFSP – a rare cancer which affects the soft tissue.

DFSP is indeed rare and often not initially recognized, according to Dr. Damon Reed, an associate member of the Sarcoma Department at Moffitt Cancer Center. “It may simply look like a bruise and may not appear overly concerning,” he said, adding that it usually does not present with any other symptoms.

Williams underwent surgery this winter to remove the cancerous tumor.

“We literally caught it within weeks of metastasizing through to my brain [and in] to my skull,” said Williams, who added the ordeal was “a scary thing to go through” and described being told by a doctor to get his affairs in order, in case he didn’t make it.

In some cases, DFSP can change from a local skin lesion to fibrosarcoma, which can spread and be fatal if not caught and removed early on.

“In addition to surgery, the chemotherapy drug imiatinib is sometimes used prior to surgery to shrink DFSP tumors to a more manageable size,” Reed said, adding that it is very effective and has been approved by the U.S. Food and Drug Administration for this indication.

Williams said surgery was the only approach, even though it meant losing 30% of his scalp. “Radiation treatment would have put a cap on my life. I think 15 years was the most I would have had after I started chemo. So I had to cut it out,” he said.

Williams said he will need to get a checkup every six months to be monitored and to make sure he is still in good health.