Being diagnosed with a brain tumor of any kind is a scary thing, but certain benign tumors rarely become dangerous. 

Recently, singer-songwriter Sheryl Crow was diagnosed with a meningioma, a fairly common non-cancerous tumor that grows from the tissue covering the brain. 

Despite the diagnosis, Crow, 50, isn't letting the tumor interrupt her nationwide tour. 

In fact, meningiomas quite often don't have to be removed at all. Crow, a breast cancer survivor, is expected to undergo periodic brain scans to monitor her tumor in the months and years to come.

"They are almost always benign tumors, and they rarely ever progress to anything beyond that," said Dr. Warren Selman, the Chairman of Neurosurgery at University Hospitals Case Medical Center.

Crow says she discovered the tumor last fall when memory problems prompted her to get a brain scan. Selman says it isn't likely the two things are related. 

"Personally, I think it's unlikely the meningioma caused the memory loss, especially if they are just observing it at this point," he said. "Usually, that's associated with a large tumor."

Meningiomas account for a third of all primary brain tumors and usually occur in adults in their 40s and 50s. Women are twice as likely to get one, and in the rare cases they get big, the tumors can cause headaches and seizures. At that point, doctors usually consider surgery to remove the tumors. 

"When anybody hears the word tumor, obviously you're going to be concerned," Selman said. "But if you have a brain tumor, this is clearly one of the ones to have."