Douglas B. Flieder, MD

Clinical Locations

Primary Location

Fox Chase Cancer Center
333 Cottman Avenue
Philadelphia, PA 19111


Professor of Pathology

Director, Surgical Pathology

Director, Autopsy Pathology

Director, Fellowship Program 


Treatment Focus

Dr. Flieder has extensive expertise in pulmonary and mediastinal diseases, having worked in these fields for more than 25 years.

Treatment Philosophy

I came to Fox Chase Cancer Center in 2004 from New York-Presbyterian Hospital in New York City to join the department of anatomic pathology and lead the division of surgical pathology. I had no hesitations leaving a prestigious university hospital for the opportunity to participate in the care of patients and participate in research at this unique and wonderful cancer center with a national presence. Not only did I join a division with exceptionally skilled world-renowned surgical pathologists, but also an institution filled with extremely talented clinicians and scientists.

As a surgical pathologist, I am responsible for diagnosing diseases, including cancer, on varying-sized tissue samples procured by clinicians. For example, my microscopic examination of a breast core biopsy uncovers the cause of mammographic calcifications. My microscopic examination of a prostate biopsy uncovers the cause of an elevated blood PSA value. Strong mutual interactions with clinicians are of paramount importance so that patients get appropriate care based on my microscopic interpretations.

While our surgical pathology laboratory primarily processes patient tissue samples for diagnosis, it also plays a key role in both clinical and basic science research at the Center. In addition to ensuring that state-of-the-art tests not offered at the Center or elsewhere in the tri-state area are available to clinicians and their patients, we also facilitate participation in many national clinical trials and research projects.

With a great interest and subspecialty training in lung diseases, I review a large number of lung biopsy and resection specimens sent from the region and around the country. I collaborate with researchers at the Center investigating causes and mechanisms of lung cancer, such as the role of estrogen in the development of lung cancer. I also participate in international studies assessing the benefits of lung cancer screening. In addition, I am active in both national and international lung pathology societies and lecture worldwide on lung pathology. I always return to Fox Chase amazed at the quality of care and research performed at this fine institution.

Education, Training & Credentials

Educational Background

  • Fellow, Pulmonary and Mediastinal Pathology, Armed Forces Institute of Pathology, and National Cancer Institute, Laboratory of Human Carcinogenesis, Washington, D.C.
  • Resident, Anatomic Pathology, Massachusetts General Hospital, Boston, MA
  • Resident, Internal Medicine, New York University/Bellevue Hospital Center, New York, NY
  • MD, University of Rochester School of Medicine and Dentistry, Rochester, NY, 1992 


  • College of American Pathologists
  • United States and Canadian Academy of Pathology
  • Pulmonary Pathology Society
  • International Association for the Study of Lung Cancer 
Research Profile

Research Interests

  • Causes and mechanisms of lung cancer
  • Lung cancer screening