The affidavit of plaintiff's expert, a board certified gynecologist and obstetrician, was sufficient to demonstrate the existence of triable issues of fact respecting plaintiff's claims for medical malpractice, which include defendant-appellant's failure to timely detect decedent's metastatic breast cancer, and thus precluded the grant of defendant Institute's motion for summary judgment as to those claims ( see, Alvarez v. Prospect Hosp., 68 N.Y.2d 320, 324; Winegrad v. New York Univ. Med. Ctr., 64 N.Y.2d 851, 852). However, plaintiff's claims against the Guttman Institute alleging that it negligently supervised and retained its employees should have been dismissed since where, as here, an employee is acting within the scope of his or her employment, thereby rendering the employer liable for any damages caused by the employee's negligence under a theory of respondeat superior, no claim may proceed against the employer for negligent hiring or retention ( Karoon v. New York City Tr. Auth., 241 A.D.2d 323).
Concur — Milonas, J. P., Ellerin, Wallach and Tom, JJ.