Medical malpractice is usually considered in terms of negligent conduct by the physician in the course of the physician-patient relation. Many of the actions are not predicated on the law of negligence, although this type of malpractice undoubtedly is the most common type of litigation. A substantial group of cases deal with unauthorized operations, which are characterized as battery, emerging from lack of informed consent.
Milton Oppenheim, Informed Consent to Medical Treatment, 11 Clev.-Marshall L. Rev. 249 (1962)