Atherton Endoscopy Center
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Our Physicians
Madhuri Badrinath
Dr. Badrinath grew up in India and moved to the U.S. for her medical training at SUNY Upstate in New York. She later served as faculty at Baylor College of Medicine before relocating to California in 2025 to be closer to family.
She treats a wide range of GI conditions and has a special interest in women’s digestive health, including pelvic floor and pregnancy-related issues. Outside of work, Dr. Badrinath enjoys rock climbing, strength training, Pilates, and exploring science beyond medicine.
She's also a trained veena artist and values time with her family, especially her nieces. She speaks English, Kannada, Hindi, and some Tamil.
Cynthia Leung
Dr. Cynthia Leung was born and raised in the Bay Area and completed her medical training, including a GI fellowship and MS in Clinical Epidemiology, at Stanford.
Her research focused on colonoscopy and GI imaging, giving her expertise in advanced technologies. She has received multiple awards, including the Housestaff Award for Professionalism.
Outside of medicine, she enjoys photography, travel, and studying Spanish.
Daniel Rengstorff
Dr. Rengstorff is a Bay Area native who completed his medical training at Georgetown, Vanderbilt, and California Pacific Medical Center.
His fellowship research focused on bleeding gastric varices and toxin-induced hepatitis. Outside of work, he enjoys golfing, skiing, woodworking, and spending time with his wife and son.
James Torosis
Dr. Torosis is a Montreal native and founder of Peninsula Gastroenterology Medical Group. He trained at McGill, completed residency in San Diego, and a GI fellowship at Yale before moving to the Peninsula in 1986.
He serves as President of the Medical Staff at Sequoia Hospital and Medical Director of Atherton Endoscopy Center. He also teaches at Stanford and enjoys mentoring future physicians.
Dr. Torosis is fluent in Greek and French, and enjoys family life with his wife, also a gastroenterologist, and their two daughters.
Vicky Yang
Dr. Yang was born in Taiwan and moved to California after high school. She earned her medical degree from Northwestern and completed her residency—serving an extra year as Chief Resident—at Santa Clara Valley Medical Center. She then completed a GI and Hepatology fellowship at Stanford and joined Peninsula Gastroenterology in 2000.
She continues to volunteer at Santa Clara Valley and is fluent in Mandarin and Taiwanese. Dr. Yang lives in the Bay Area with her husband and two sons.