Our Staff

Dr. Gordon has been a rheumatologist at Lankenau Hospital since 1982 and is currently the chief of the rheumatology section. He earned a BA from Brown University and M.D. from Yale School of Medicine. Dr. Gordon did his rheumatology fellowship at the University of Pennsylvania, has published articles in medical journals, written chapters in textbooks in the field of rheumatology, and is a well-respected and frequent lecturer throughout the country. He is a fellow in the American College of Rheumatology and The American College of Physicians. Dr. Gordon has been listed as a “Top Doctor” in Philadelphia Magazine and in the Main Line Today Magazine for many years. He is married with four children.

Dr. Thomas Harder has practiced Rheumatology on The Main Line since 2000. Named numerous times as a “Top Doctor” in Philadelphia Magazine’s “Best of Philly,” he is committed to educating his patients and helping them manage their medical problems, including all inflammatory or degenerative arthritic processes, soft tissue rheumatism and osteoporosis. Dr. Harder completed his Rheumatology training at UCLA/Sepulveda in Los Angeles in 2000, and became Board Certified in Internal Medicine in 1992, and in Rheumatology in 2001. He grew up in a beautiful, small river town in southeastern Ohio, and graduated from Ohio University, summa cum laude and Phi Beta Kappa. Dr. Harder earned his medical degree from The Ohio State University, and for many years practiced Internal Medicine in Columbus, Ohio, and won awards as an educator. Outside the realm of traditional Rheumatology, he has a passion for teaching patients how to maintain proper physical fitness through strength training and proper flexibility exercises. Dr. Harder resides on The Main Line with his wife Debra and their two daughters. They enjoy gardening, hiking, the arts, and spending time with friends.

Dr. Lundholm is a board certified Rheumatologist working in private practice for the past 12 years. Dr. Lundholm graduated from New York University with a BA in Psychology and completed her medical training at the Lake Erie College of Osteopathic Medicine. She was an Internal Medicine resident at Lankenau Hospital, following with fellowship in Rheumatology at Roger Williams Medical Center and Rhode Island Hospital. During her fellowship, she spent additional time learning how to care for rheumatology patients during pregnancy at Women and Infants Hospital in Providence, RI. Dr. Lundholm has co-authored papers on spondyloathropathies. She has a clinical interest in inflammatory arthritis, osteoporosis and women’s health.

Dr Lundholm has been named Philadelphia Magazine Top Doctor 2023-2026 and Main Line Today Magazine Top Doctor 2018-2026.

Dr. Hyon Ju Park is board certified in rheumatology and internal medicine, and is certified in Clinical Densitometry (bone density studies). Dr. Park graduated Columbia University in 2003 with a degree in biochemistry, and graduated Mount Sinai School of Medicine in New York, in 2007. She completed a residency in Internal Medicine at Barnes Jewish Hospital in St. Louis, Missouri as well as a rheumatology fellowship and additional research fellowship at Washington University in St. Louis, Missouri. Dr. Park has been an avid contributor to medical publishing including editorials, reviews, case reports and many book chapters. She has a special interest in lupus, vasculitis, and periodic fever syndromes.

Dr. Tanya Harari specializes in the diagnosis and treatment of osteoporosis, scleroderma, rheumatoid arthritis, systemic lupus erythematosus, spondyloarthritis, and osteoarthritis. She is committed to providing compassionate, evidence-based care and helping patients understand their conditions and treatment options so they can make informed decisions about their health. In addition to caring for patients, Dr. Harari is passionate about medical education and enjoys teaching and mentoring medical residents and trainees. Dr. Harari received her medical degree from Edward Via College of Osteopathic Medicine, completed her Internal Medicine residency at the University of Pennsylvania, and completed her Rheumatology fellowship at Thomas Jefferson University. In recognition of her commitment to outstanding patient care, Dr. Harari was named a Main Line Today Top Doctor.

Dr. Marissa Karpoff is board-certified in rheumatology and internal medicine. She graduated from Cornell University with a B.S. in animal science and completed medical training at Tulane University School of Medicine. Dr. Karpoff went on to complete her internal medicine residency at the Icahn School of Medicine at Mount Sinai followed by rheumatology fellowship at the Hospital at the University of Pennsylvania. Prior to joining MLRO, she worked as an attending rheumatologist at Cooper University Hospital for 7 years. She is committed to treating patients with autoimmune rheumatic disease and bone disorders. She enjoys seeing patients with a wide variety of conditions including rheumatoid arthritis, psoriatic arthritis, osteoporosis, lupus, myositis, vasculitis, gout, and osteoarthritis. She has a particular interest in geriatric rheumatology as well as reproductive healthcare and women’s health within rheumatology. She has extensive teaching experience and also enjoys empowering her patients to better understand their health.