Meet The Doctors

Dr. Frank R. Crantz, M.D.

Dr Crantz is a native of Detroit, Michigan. He completed his undergraduate degree at the University of Michigan in Ann Arbor. He then spent two years at Cambridge University in Cambridge, England, where he received his Masters Degree. Dr Crantz received his medical degree from Johns Hopkins University School of Medicine in Baltimore, Maryland. He completed his internship and residency in Medicine at The New York Hospital, Cornell University Medical College in New York City. From 1978-1981 he was a Research Fellow in Endocrinology at Harvard Medical School in Boston, Massachusetts. He completed his Endocrine fellowship at the Brigham and Women’s Hospital in Boston. From 1981-1983 Dr Crantz was the Endocrinologist in Charge at Queens Hospital Center and an Assistant Professor of Medicine at SUNY at Stony Brook. He began his endocrine practice in Northern Virginia in 1983 and is one of the founding members of Endocrine Associates. He is a Fellow of the American College of the Physicians and the American College of Endocrinology. He is a Clinical Associate Professor of Medicine at Georgetown University School of Medicine. Dr Crantz is a member of the Endocrine Society, the American Diabetes Association, the American Thyroid Association and the American Association of Clinical Endocrinologists. He is a Past President of the American Diabetes Association, D.C. Area Affiliate. He has done original research in the areas of thyroid disease and Endocrine hypertension.

Dr. S. Mark Tanen, M.D., FRCP(C), FACE, LLC

Dr. Tanen was born in New Haven, Connecticut in 1959. He was raised in Toronto, Canada where he completed his medical training. After a Fellowship at the National Institutes of Health in Bethesda, MD he joined Endocrine Associates in 1989. Dr. Tanen is on staff at INOVA Fairfax Hospital and is a Clinical Assistant Professor at the Georgetown University Faculty of Medicine.