CORAL GABLES, Fla. -

A Coral Gables man is demanding answers after his mother, who is battling cancer, was released from a hospital badly bruised.

Isel Ferro, 73, doesn't remember much about the incident and said she just "heard a pop and then felt lots of pain."

Her son says the large knot on her forehead is about half the size it was when he first saw it Sunday.

Carlos Vazquez says the incident happened while his mother was at Doctors Hospital in Coral Gables, but how it happened is unclear.  His mother says she recalls ringing the nurses’ station several times from her hospital bed in the middle of the night because she had to go to the bathroom. Staffers have only told her son she fell.

Ferro was admitted to Doctor's Hospital on May 13 after having some complications with her chemotherapy treatment. Her son believes her head was injured one week ago.

Vazquez is now trying to obtain his mother's medical records, hoping it might some shed light on why she left the hospital in worse shape than when she went in.

The hospital has since released this statement: "We are aware of the public statements by Mrs. Ferro and her family regarding Doctors Hospital. The safe care of our patients is our top priority. While we disagree with the family's statements, we are taking them very seriously, and are in communication with Mrs. Ferro and her family to address them. Due to patient privacy laws we cannot provide additional information regarding Mrs. Ferro, unless she gives us written authorization to do so. We will continue to be in touch with the family to ensure that they have accurate information."