After House is ostensibly thrown off of Arlene Cuddy's case, he has to distract Martha M. Masters who will obviously squeal on him once she finds out they're still working on the case. As a result, he pretends that Stuart may have a treatable condition and manipulates Masters into running an invasive test in violation of a standing order not to do tests without the family's consent.
When Masters eventually finds out that House is working on Arlene's case, she does threaten to tell her formal attending Dr. Kaufman about House's deception. At that point, House reveals that Masters is guilty of assault on the patient and he will make sure charges are pressed against her, ruining her medical career.
Masters is so upset she vomits in the nearest toilet. However, she tells Dr. Kaufman anyway.