Dozens of cases have been identified.
Experts are looking into a group of ocular melanoma cases that have occurred in Huntersville, NC, and Auburn, AL.
More than 50 people in the two cities combined have developed the rare cancer, CNN reports. And 38 of them reportedly were students at Auburn University between 1983 and 2001.
Dr. Marlana Orloff, an oncologist treating some of the patients, said the situation is "a unique accumulation of cases" although it's not officially being classified as a cancer cluster at this point. She said it's not clear what has caused the cancer.
Four of the patients have died.
CNN quoted a statement from Auburn University saying it is "working closely with the Alabama Department of Public Health, which is leading the review of area cases of uveal melanoma."
Read more at CNN