Val Kilmer's family reportedly thinks the actor is neglecting his health because of his commitment to the Christian Science faith.
Family members told TMZ that Kilmer, 55, has suffered symptoms from the tumor since last summer, but has refused to seek medical treatment because Christian Scientists believe prayer should be used instead.
The gossip site previously reported that the Top Gun and Batman Forever star was hospitalized last week in Los Angeles after he started bleeding from his throat.
But Kilmer took to Facebook shortly afterward to deny reports that he had a tumor, writing: "I have not had a tumor, or a tumor operations, or any operation. I had a complication where the best way to receive care was to stay under the watchful eye of the ucla ICU."
"Friends have assisted who know my spiritual convictions and have been most sensitive and kind for the extra effort in making sure there's minimum gossip and silly talk," he added.