Despite the severity of the news that Sheryl Crow has been diagnosed with a brain tumor, the good news is that the type of tumor, a meningioma, is non-cancerous.

MTV News caught up with Dr. Alessandro Olivi, a professor of neurosurgery and director of the Meningioma Center at Johns Hopkins University, who spoke very positively about Crow's prognosis.

"If they elected to observe it [and not perform surgery], that means the tumor is an incidental finding and considered, like it is in the majority of these cases, biologically favorable," Olivi said. "It's benign and doesn't need to come out, because it's not causing any problems and can be monitored safely."

Olivi, who also serves as the vice chairman of the department of neurosurgery at Johns Hopkins, went on to say that doctors don't yet know what specifically causes the tumors, just that they tend to occur in women and that estrogen might play a role.

"We don't know what causes them. We know that there is preponderance in women over men. Some people have said it's related to estrogen. There might be some receptor, but not to the point where I would say to change hormone treatment," he said. "For example, with menopause, you produce less estrogen and people are on hormone replacement. I don't consider that a reason not to do it. In other words, the correlation [between estrogen and meningioma] is loose. We don't know in reality what the cause is. The good thing is that in the vast majority, they are self-limiting, and the biological behavior is not one of an aggressive cancer."

Speaking to how the tumor will affect Crow's day-to-day lifestyle moving forward, Olivi said she'll likely only need routine checkups.

"She just needs to do what she is told as far as monitoring and imaging, which will probably be once every six months if everything is OK and can be moved up to once a year," he said. "But no change in lifestyle; she can still sing!"